postgresql/src/backend/utils/adt/domains.c

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/*-------------------------------------------------------------------------
*
* domains.c
* I/O functions for domain types.
*
* The output functions for a domain type are just the same ones provided
* by its underlying base type. The input functions, however, must be
* prepared to apply any constraints defined by the type. So, we create
* special input functions that invoke the base type's input function
* and then check the constraints.
*
* The overhead required for constraint checking can be high, since examining
* the catalogs to discover the constraints for a given domain is not cheap.
* We have three mechanisms for minimizing this cost:
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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* 1. We rely on the typcache to keep up-to-date copies of the constraints.
* 2. In a nest of domains, we flatten the checking of all the levels
* into just one operation (the typcache does this for us).
* 3. If there are CHECK constraints, we cache a standalone ExprContext
* to evaluate them in.
*
*
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* Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
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* src/backend/utils/adt/domains.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/htup_details.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "lib/stringinfo.h"
#include "utils/builtins.h"
#include "utils/expandeddatum.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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#include "utils/typcache.h"
/*
* structure to cache state across multiple calls
*/
typedef struct DomainIOData
{
Oid domain_type;
/* Data needed to call base type's input function */
Oid typiofunc;
Oid typioparam;
int32 typtypmod;
FmgrInfo proc;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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/* Reference to cached list of constraint items to check */
DomainConstraintRef constraint_ref;
/* Context for evaluating CHECK constraints in */
ExprContext *econtext;
/* Memory context this cache is in */
MemoryContext mcxt;
} DomainIOData;
/*
* domain_state_setup - initialize the cache for a new domain type.
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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*
* Note: we can't re-use the same cache struct for a new domain type,
* since there's no provision for releasing the DomainConstraintRef.
* If a call site needs to deal with a new domain type, we just leak
* the old struct for the duration of the query.
*/
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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static DomainIOData *
domain_state_setup(Oid domainType, bool binary, MemoryContext mcxt)
{
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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DomainIOData *my_extra;
TypeCacheEntry *typentry;
Oid baseType;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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my_extra = (DomainIOData *) MemoryContextAlloc(mcxt, sizeof(DomainIOData));
/*
* Verify that domainType represents a valid domain type. We need to be
* careful here because domain_in and domain_recv can be called from SQL,
* possibly with incorrect arguments. We use lookup_type_cache mainly
* because it will throw a clean user-facing error for a bad OID.
*/
typentry = lookup_type_cache(domainType, 0);
if (typentry->typtype != TYPTYPE_DOMAIN)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("type %s is not a domain",
format_type_be(domainType))));
/* Find out the base type */
my_extra->typtypmod = -1;
baseType = getBaseTypeAndTypmod(domainType, &my_extra->typtypmod);
/* Look up underlying I/O function */
if (binary)
getTypeBinaryInputInfo(baseType,
&my_extra->typiofunc,
&my_extra->typioparam);
else
getTypeInputInfo(baseType,
&my_extra->typiofunc,
&my_extra->typioparam);
fmgr_info_cxt(my_extra->typiofunc, &my_extra->proc, mcxt);
/* Look up constraints for domain */
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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InitDomainConstraintRef(domainType, &my_extra->constraint_ref, mcxt);
/* We don't make an ExprContext until needed */
my_extra->econtext = NULL;
my_extra->mcxt = mcxt;
/* Mark cache valid */
my_extra->domain_type = domainType;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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return my_extra;
}
/*
* domain_check_input - apply the cached checks.
*
* This is extremely similar to ExecEvalCoerceToDomain in execQual.c.
*/
static void
domain_check_input(Datum value, bool isnull, DomainIOData *my_extra)
{
ExprContext *econtext = my_extra->econtext;
ListCell *l;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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/* Make sure we have up-to-date constraints */
UpdateDomainConstraintRef(&my_extra->constraint_ref);
foreach(l, my_extra->constraint_ref.constraints)
{
DomainConstraintState *con = (DomainConstraintState *) lfirst(l);
switch (con->constrainttype)
{
case DOM_CONSTRAINT_NOTNULL:
if (isnull)
ereport(ERROR,
(errcode(ERRCODE_NOT_NULL_VIOLATION),
errmsg("domain %s does not allow null values",
format_type_be(my_extra->domain_type)),
errdatatype(my_extra->domain_type)));
break;
case DOM_CONSTRAINT_CHECK:
{
Datum conResult;
bool conIsNull;
/* Make the econtext if we didn't already */
if (econtext == NULL)
{
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(my_extra->mcxt);
econtext = CreateStandaloneExprContext();
MemoryContextSwitchTo(oldcontext);
my_extra->econtext = econtext;
}
/*
* Set up value to be returned by CoerceToDomainValue
* nodes. Unlike ExecEvalCoerceToDomain, this econtext
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* couldn't be shared with anything else, so no need to
* save and restore fields. But we do need to protect the
* passed-in value against being changed by called
* functions. (It couldn't be a R/W expanded object for
* most uses, but that seems possible for domain_check().)
*/
econtext->domainValue_datum =
MakeExpandedObjectReadOnly(value, isnull,
my_extra->constraint_ref.tcache->typlen);
econtext->domainValue_isNull = isnull;
conResult = ExecEvalExprSwitchContext(con->check_expr,
econtext,
&conIsNull);
if (!conIsNull &&
!DatumGetBool(conResult))
ereport(ERROR,
(errcode(ERRCODE_CHECK_VIOLATION),
errmsg("value for domain %s violates check constraint \"%s\"",
format_type_be(my_extra->domain_type),
con->name),
errdomainconstraint(my_extra->domain_type,
con->name)));
break;
}
default:
elog(ERROR, "unrecognized constraint type: %d",
(int) con->constrainttype);
break;
}
}
/*
* Before exiting, call any shutdown callbacks and reset econtext's
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* per-tuple memory. This avoids leaking non-memory resources, if
* anything in the expression(s) has any.
*/
if (econtext)
ReScanExprContext(econtext);
}
/*
* domain_in - input routine for any domain type.
*/
Datum
domain_in(PG_FUNCTION_ARGS)
{
char *string;
Oid domainType;
DomainIOData *my_extra;
Datum value;
/*
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* Since domain_in is not strict, we have to check for null inputs. The
* typioparam argument should never be null in normal system usage, but it
* could be null in a manual invocation --- if so, just return null.
*/
if (PG_ARGISNULL(0))
string = NULL;
else
string = PG_GETARG_CSTRING(0);
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
domainType = PG_GETARG_OID(1);
/*
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* We arrange to look up the needed info just once per series of calls,
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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* assuming the domain type doesn't change underneath us (which really
* shouldn't happen, but cope if it does).
*/
my_extra = (DomainIOData *) fcinfo->flinfo->fn_extra;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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if (my_extra == NULL || my_extra->domain_type != domainType)
{
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
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my_extra = domain_state_setup(domainType, false,
fcinfo->flinfo->fn_mcxt);
fcinfo->flinfo->fn_extra = (void *) my_extra;
}
/*
* Invoke the base type's typinput procedure to convert the data.
*/
value = InputFunctionCall(&my_extra->proc,
string,
my_extra->typioparam,
my_extra->typtypmod);
/*
* Do the necessary checks to ensure it's a valid domain value.
*/
domain_check_input(value, (string == NULL), my_extra);
if (string == NULL)
PG_RETURN_NULL();
else
PG_RETURN_DATUM(value);
}
/*
* domain_recv - binary input routine for any domain type.
*/
Datum
domain_recv(PG_FUNCTION_ARGS)
{
StringInfo buf;
Oid domainType;
DomainIOData *my_extra;
Datum value;
/*
2006-10-04 02:30:14 +02:00
* Since domain_recv is not strict, we have to check for null inputs. The
* typioparam argument should never be null in normal system usage, but it
* could be null in a manual invocation --- if so, just return null.
*/
if (PG_ARGISNULL(0))
buf = NULL;
else
buf = (StringInfo) PG_GETARG_POINTER(0);
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
domainType = PG_GETARG_OID(1);
/*
2006-10-04 02:30:14 +02:00
* We arrange to look up the needed info just once per series of calls,
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
2015-03-01 20:06:50 +01:00
* assuming the domain type doesn't change underneath us (which really
* shouldn't happen, but cope if it does).
*/
my_extra = (DomainIOData *) fcinfo->flinfo->fn_extra;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
2015-03-01 20:06:50 +01:00
if (my_extra == NULL || my_extra->domain_type != domainType)
{
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
2015-03-01 20:06:50 +01:00
my_extra = domain_state_setup(domainType, true,
fcinfo->flinfo->fn_mcxt);
fcinfo->flinfo->fn_extra = (void *) my_extra;
}
/*
* Invoke the base type's typreceive procedure to convert the data.
*/
value = ReceiveFunctionCall(&my_extra->proc,
buf,
my_extra->typioparam,
my_extra->typtypmod);
/*
* Do the necessary checks to ensure it's a valid domain value.
*/
domain_check_input(value, (buf == NULL), my_extra);
if (buf == NULL)
PG_RETURN_NULL();
else
PG_RETURN_DATUM(value);
}
/*
* domain_check - check that a datum satisfies the constraints of a
* domain. extra and mcxt can be passed if they are available from,
* say, a FmgrInfo structure, or they can be NULL, in which case the
* setup is repeated for each call.
*/
void
domain_check(Datum value, bool isnull, Oid domainType,
void **extra, MemoryContext mcxt)
{
DomainIOData *my_extra = NULL;
if (mcxt == NULL)
mcxt = CurrentMemoryContext;
/*
* We arrange to look up the needed info just once per series of calls,
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
2015-03-01 20:06:50 +01:00
* assuming the domain type doesn't change underneath us (which really
* shouldn't happen, but cope if it does).
*/
if (extra)
my_extra = (DomainIOData *) *extra;
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
2015-03-01 20:06:50 +01:00
if (my_extra == NULL || my_extra->domain_type != domainType)
{
Use the typcache to cache constraints for domain types. Previously, we cached domain constraints for the life of a query, or really for the life of the FmgrInfo struct that was used to invoke domain_in() or domain_check(). But plpgsql (and probably other places) are set up to cache such FmgrInfos for the whole lifespan of a session, which meant they could be enforcing really stale sets of constraints. On the other hand, searching pg_constraint once per query gets kind of expensive too: testing says that as much as half the runtime of a trivial query such as "SELECT 0::domaintype" went into that. To fix this, delegate the responsibility for tracking a domain's constraints to the typcache, which has the infrastructure needed to detect syscache invalidation events that signal possible changes. This not only removes unnecessary repeat reads of pg_constraint, but ensures that we never apply stale constraint data: whatever we use is the current data according to syscache rules. Unfortunately, the current configuration of the system catalogs means we have to flush cached domain-constraint data whenever either pg_type or pg_constraint changes, which happens rather a lot (eg, creation or deletion of a temp table will do it). It might be worth rearranging things to split pg_constraint into two catalogs, of which the domain constraint one would probably be very low-traffic. That's a job for another patch though, and in any case this patch should improve matters materially even with that handicap. This patch makes use of the recently-added memory context reset callback feature to manage the lifespan of domain constraint caches, so that we don't risk deleting a cache that might be in the midst of evaluation. Although this is a bug fix as well as a performance improvement, no back-patch. There haven't been many if any field complaints about stale domain constraint checks, so it doesn't seem worth taking the risk of modifying data structures as basic as MemoryContexts in back branches.
2015-03-01 20:06:50 +01:00
my_extra = domain_state_setup(domainType, true, mcxt);
if (extra)
*extra = (void *) my_extra;
}
/*
* Do the necessary checks to ensure it's a valid domain value.
*/
domain_check_input(value, isnull, my_extra);
}
/*
* errdatatype --- stores schema_name and datatype_name of a datatype
* within the current errordata.
*/
int
errdatatype(Oid datatypeOid)
{
HeapTuple tup;
Form_pg_type typtup;
tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(datatypeOid));
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for type %u", datatypeOid);
typtup = (Form_pg_type) GETSTRUCT(tup);
err_generic_string(PG_DIAG_SCHEMA_NAME,
get_namespace_name(typtup->typnamespace));
err_generic_string(PG_DIAG_DATATYPE_NAME, NameStr(typtup->typname));
ReleaseSysCache(tup);
return 0; /* return value does not matter */
}
/*
* errdomainconstraint --- stores schema_name, datatype_name and
* constraint_name of a domain-related constraint within the current errordata.
*/
int
errdomainconstraint(Oid datatypeOid, const char *conname)
{
errdatatype(datatypeOid);
err_generic_string(PG_DIAG_CONSTRAINT_NAME, conname);
return 0; /* return value does not matter */
}