postgresql/contrib/pageinspect/gistfuncs.c
Michael Paquier e7bff46e50 pageinspect: Fix gist_page_items() with included columns
Non-leaf pages of GiST indexes contain key attributes, leaf pages
contain both key and non-key attributes, and gist_page_items() ignored
the handling of non-key attributes.  This caused a few problems when
using gist_page_items() on a GiST index with INCLUDE:
- On a non-leaf page, the function would crash.
- On a leaf page, the function would work, but miss to display all the
values for included attributes.

This commit fixes gist_page_items() to handle such cases in a more
appropriate way, and now displays the values of key and non-key
attributes for each item separately in a style consistent with what
ruleutils.c would generate for the attribute list, depending on the page
type dealt with.  In a way similar to how a record is displayed, values
would be double-quoted for key or non-key attributes if required.

ruleutils.c did not provide a routine able to control if non-key
attributes should be displayed, so an extended() routine for index
definitions is added to work around the leaf and non-leaf page
differences.

While on it, this commit fixes a third problem related to the amount of
data reported for key attributes.  The code originally relied on
BuildIndexValueDescription() (used for error reports on constraints)
that would not print all the data stored in the index but the index
opclass's input type, so this limited the amount of information
available.  This switch makes gist_page_items() much cheaper as there is
no need to run ACL checks for each item printed, which is not an issue
anyway as superuser rights are required to execute the functions of
pageinspect.  Opclasses whose data cannot be displayed can rely on
gist_page_items_bytea().

The documentation of this function was slightly incorrect for the
output results generated on HEAD and v15, so adjust it on these
branches.

Author: Alexander Lakhin, Michael Paquier
Discussion: https://postgr.es/m/17884-cb8c326522977acb@postgresql.org
Backpatch-through: 14
2023-05-19 12:37:58 +09:00

370 lines
9.2 KiB
C

/*
* gistfuncs.c
* Functions to investigate the content of GiST indexes
*
* Copyright (c) 2014-2023, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/pageinspect/gistfuncs.c
*/
#include "postgres.h"
#include "access/gist.h"
#include "access/gist_private.h"
#include "access/htup.h"
#include "access/relation.h"
#include "catalog/namespace.h"
#include "catalog/pg_am_d.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "pageinspect.h"
#include "storage/itemptr.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/pg_lsn.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/ruleutils.h"
#include "utils/varlena.h"
PG_FUNCTION_INFO_V1(gist_page_opaque_info);
PG_FUNCTION_INFO_V1(gist_page_items);
PG_FUNCTION_INFO_V1(gist_page_items_bytea);
#define IS_GIST(r) ((r)->rd_rel->relam == GIST_AM_OID)
static Page verify_gist_page(bytea *raw_page);
/*
* Verify that the given bytea contains a GIST page or die in the attempt.
* A pointer to the page is returned.
*/
static Page
verify_gist_page(bytea *raw_page)
{
Page page = get_page_from_raw(raw_page);
GISTPageOpaque opaq;
if (PageIsNew(page))
return page;
/* verify the special space has the expected size */
if (PageGetSpecialSize(page) != MAXALIGN(sizeof(GISTPageOpaqueData)))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a valid %s page", "GiST"),
errdetail("Expected special size %d, got %d.",
(int) MAXALIGN(sizeof(GISTPageOpaqueData)),
(int) PageGetSpecialSize(page))));
opaq = GistPageGetOpaque(page);
if (opaq->gist_page_id != GIST_PAGE_ID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a valid %s page", "GiST"),
errdetail("Expected %08x, got %08x.",
GIST_PAGE_ID,
opaq->gist_page_id)));
return page;
}
Datum
gist_page_opaque_info(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
TupleDesc tupdesc;
Page page;
HeapTuple resultTuple;
Datum values[4];
bool nulls[4];
Datum flags[16];
int nflags = 0;
uint16 flagbits;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
page = verify_gist_page(raw_page);
if (PageIsNew(page))
PG_RETURN_NULL();
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* Convert the flags bitmask to an array of human-readable names */
flagbits = GistPageGetOpaque(page)->flags;
if (flagbits & F_LEAF)
flags[nflags++] = CStringGetTextDatum("leaf");
if (flagbits & F_DELETED)
flags[nflags++] = CStringGetTextDatum("deleted");
if (flagbits & F_TUPLES_DELETED)
flags[nflags++] = CStringGetTextDatum("tuples_deleted");
if (flagbits & F_FOLLOW_RIGHT)
flags[nflags++] = CStringGetTextDatum("follow_right");
if (flagbits & F_HAS_GARBAGE)
flags[nflags++] = CStringGetTextDatum("has_garbage");
flagbits &= ~(F_LEAF | F_DELETED | F_TUPLES_DELETED | F_FOLLOW_RIGHT | F_HAS_GARBAGE);
if (flagbits)
{
/* any flags we don't recognize are printed in hex */
flags[nflags++] = DirectFunctionCall1(to_hex32, Int32GetDatum(flagbits));
}
memset(nulls, 0, sizeof(nulls));
values[0] = LSNGetDatum(PageGetLSN(page));
values[1] = LSNGetDatum(GistPageGetNSN(page));
values[2] = Int64GetDatum(GistPageGetOpaque(page)->rightlink);
values[3] = PointerGetDatum(construct_array_builtin(flags, nflags, TEXTOID));
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(tupdesc, values, nulls);
return HeapTupleGetDatum(resultTuple);
}
Datum
gist_page_items_bytea(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
Page page;
OffsetNumber offset;
OffsetNumber maxoff = InvalidOffsetNumber;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
InitMaterializedSRF(fcinfo, 0);
page = verify_gist_page(raw_page);
if (PageIsNew(page))
PG_RETURN_NULL();
/* Avoid bogus PageGetMaxOffsetNumber() call with deleted pages */
if (GistPageIsDeleted(page))
elog(NOTICE, "page is deleted");
else
maxoff = PageGetMaxOffsetNumber(page);
for (offset = FirstOffsetNumber;
offset <= maxoff;
offset++)
{
Datum values[5];
bool nulls[5];
ItemId id;
IndexTuple itup;
bytea *tuple_bytea;
int tuple_len;
id = PageGetItemId(page, offset);
if (!ItemIdIsValid(id))
elog(ERROR, "invalid ItemId");
itup = (IndexTuple) PageGetItem(page, id);
tuple_len = IndexTupleSize(itup);
memset(nulls, 0, sizeof(nulls));
values[0] = DatumGetInt16(offset);
values[1] = ItemPointerGetDatum(&itup->t_tid);
values[2] = Int32GetDatum((int) IndexTupleSize(itup));
tuple_bytea = (bytea *) palloc(tuple_len + VARHDRSZ);
SET_VARSIZE(tuple_bytea, tuple_len + VARHDRSZ);
memcpy(VARDATA(tuple_bytea), itup, tuple_len);
values[3] = BoolGetDatum(ItemIdIsDead(id));
values[4] = PointerGetDatum(tuple_bytea);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}
return (Datum) 0;
}
Datum
gist_page_items(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
Oid indexRelid = PG_GETARG_OID(1);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
Relation indexRel;
TupleDesc tupdesc;
Page page;
uint16 flagbits;
bits16 printflags = 0;
OffsetNumber offset;
OffsetNumber maxoff = InvalidOffsetNumber;
char *index_columns;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to use raw page functions")));
InitMaterializedSRF(fcinfo, 0);
/* Open the relation */
indexRel = index_open(indexRelid, AccessShareLock);
if (!IS_GIST(indexRel))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a %s index",
RelationGetRelationName(indexRel), "GiST")));
page = verify_gist_page(raw_page);
if (PageIsNew(page))
{
index_close(indexRel, AccessShareLock);
PG_RETURN_NULL();
}
flagbits = GistPageGetOpaque(page)->flags;
/*
* Included attributes are added when dealing with leaf pages, discarded
* for non-leaf pages as these include only data for key attributes.
*/
printflags |= RULE_INDEXDEF_PRETTY;
if (flagbits & F_LEAF)
{
tupdesc = RelationGetDescr(indexRel);
}
else
{
tupdesc = CreateTupleDescCopy(RelationGetDescr(indexRel));
tupdesc->natts = IndexRelationGetNumberOfKeyAttributes(indexRel);
printflags |= RULE_INDEXDEF_KEYS_ONLY;
}
index_columns = pg_get_indexdef_columns_extended(indexRelid,
printflags);
/* Avoid bogus PageGetMaxOffsetNumber() call with deleted pages */
if (GistPageIsDeleted(page))
elog(NOTICE, "page is deleted");
else
maxoff = PageGetMaxOffsetNumber(page);
for (offset = FirstOffsetNumber;
offset <= maxoff;
offset++)
{
Datum values[5];
bool nulls[5];
ItemId id;
IndexTuple itup;
Datum itup_values[INDEX_MAX_KEYS];
bool itup_isnull[INDEX_MAX_KEYS];
StringInfoData buf;
int i;
id = PageGetItemId(page, offset);
if (!ItemIdIsValid(id))
elog(ERROR, "invalid ItemId");
itup = (IndexTuple) PageGetItem(page, id);
index_deform_tuple(itup, tupdesc,
itup_values, itup_isnull);
memset(nulls, 0, sizeof(nulls));
values[0] = DatumGetInt16(offset);
values[1] = ItemPointerGetDatum(&itup->t_tid);
values[2] = Int32GetDatum((int) IndexTupleSize(itup));
values[3] = BoolGetDatum(ItemIdIsDead(id));
if (index_columns)
{
initStringInfo(&buf);
appendStringInfo(&buf, "(%s)=(", index_columns);
/* Most of this is copied from record_out(). */
for (i = 0; i < tupdesc->natts; i++)
{
char *value;
char *tmp;
bool nq = false;
if (itup_isnull[i])
value = "null";
else
{
Oid foutoid;
bool typisvarlena;
Oid typoid;
typoid = tupdesc->attrs[i].atttypid;
getTypeOutputInfo(typoid, &foutoid, &typisvarlena);
value = OidOutputFunctionCall(foutoid, itup_values[i]);
}
if (i == IndexRelationGetNumberOfKeyAttributes(indexRel))
appendStringInfoString(&buf, ") INCLUDE (");
else if (i > 0)
appendStringInfoString(&buf, ", ");
/* Check whether we need double quotes for this value */
nq = (value[0] == '\0'); /* force quotes for empty string */
for (tmp = value; *tmp; tmp++)
{
char ch = *tmp;
if (ch == '"' || ch == '\\' ||
ch == '(' || ch == ')' || ch == ',' ||
isspace((unsigned char) ch))
{
nq = true;
break;
}
}
/* And emit the string */
if (nq)
appendStringInfoCharMacro(&buf, '"');
for (tmp = value; *tmp; tmp++)
{
char ch = *tmp;
if (ch == '"' || ch == '\\')
appendStringInfoCharMacro(&buf, ch);
appendStringInfoCharMacro(&buf, ch);
}
if (nq)
appendStringInfoCharMacro(&buf, '"');
}
appendStringInfoChar(&buf, ')');
values[4] = CStringGetTextDatum(buf.data);
nulls[4] = false;
}
else
{
values[4] = (Datum) 0;
nulls[4] = true;
}
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}
relation_close(indexRel, AccessShareLock);
return (Datum) 0;
}