postgresql/src/backend/parser/analyze.c

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/*-------------------------------------------------------------------------
*
* analyze.c--
* transform the parse tree into a query tree
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.52 1997/12/04 23:07:18 thomas Exp $
*
*-------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
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#include "postgres.h"
#include "access/heapam.h"
#include "nodes/makefuncs.h"
#include "nodes/memnodes.h"
#include "nodes/pg_list.h"
#include "parser/analyze.h"
#include "parser/parse_agg.h"
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#include "parser/parse_clause.h"
#include "parser/parse_node.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "utils/builtins.h"
#include "utils/mcxt.h"
static Query *transformStmt(ParseState *pstate, Node *stmt);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
static Query *transformInsertStmt(ParseState *pstate, AppendStmt *stmt);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
static Query *transformExtendStmt(ParseState *pstate, ExtendStmt *stmt);
static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt);
static Query *transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, ReplaceStmt *stmt);
static Query *transformCursorStmt(ParseState *pstate, CursorStmt *stmt);
static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
List *extras = NIL;
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/*
* parse_analyze -
* analyze a list of parse trees and transform them if necessary.
*
* Returns a list of transformed parse trees. Optimizable statements are
* all transformed to Query while the rest stays the same.
*
* CALLER is responsible for freeing the QueryTreeList* returned
*/
QueryTreeList *
parse_analyze(List *pl)
{
QueryTreeList *result;
ParseState *pstate;
int i = 0;
result = malloc(sizeof(QueryTreeList));
result->len = length(pl);
result->qtrees = (Query **) malloc(result->len * sizeof(Query *));
while (pl != NIL)
{
pstate = make_parsestate();
result->qtrees[i++] = transformStmt(pstate, lfirst(pl));
if (extras != NIL)
{
result->len += length(extras);
result->qtrees = (Query **) realloc(result->qtrees, result->len * sizeof(Query *));
while (extras != NIL)
{
result->qtrees[i++] = transformStmt(pstate, lfirst(extras));
extras = lnext(extras);
}
}
extras = NIL;
pl = lnext(pl);
if (pstate->p_target_relation != NULL)
heap_close(pstate->p_target_relation);
free(pstate);
}
return result;
}
/*
* transformStmt -
* transform a Parse tree. If it is an optimizable statement, turn it
* into a Query tree.
*/
static Query *
transformStmt(ParseState *pstate, Node *parseTree)
{
Query *result = NULL;
switch (nodeTag(parseTree))
{
/*------------------------
* Non-optimizable statements
*------------------------
*/
case T_CreateStmt:
result = transformCreateStmt(pstate, (CreateStmt *) parseTree);
break;
case T_IndexStmt:
result = transformIndexStmt(pstate, (IndexStmt *) parseTree);
break;
case T_ExtendStmt:
result = transformExtendStmt(pstate, (ExtendStmt *) parseTree);
break;
case T_RuleStmt:
result = transformRuleStmt(pstate, (RuleStmt *) parseTree);
break;
case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;
n->query = (Query *) transformStmt(pstate, (Node *) n->query);
result = makeNode(Query);
result->commandType = CMD_UTILITY;
result->utilityStmt = (Node *) n;
}
break;
case T_VacuumStmt:
{
MemoryContext oldcontext;
/*
* make sure that this Query is allocated in TopMemory
* context because vacuum spans transactions and we don't
* want to lose the vacuum Query due to end-of-transaction
* free'ing
*/
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
result = makeNode(Query);
result->commandType = CMD_UTILITY;
result->utilityStmt = (Node *) parseTree;
MemoryContextSwitchTo(oldcontext);
break;
}
case T_ExplainStmt:
{
ExplainStmt *n = (ExplainStmt *) parseTree;
result = makeNode(Query);
result->commandType = CMD_UTILITY;
n->query = transformStmt(pstate, (Node *) n->query);
result->utilityStmt = (Node *) parseTree;
}
break;
/*------------------------
* Optimizable statements
*------------------------
*/
case T_AppendStmt:
result = transformInsertStmt(pstate, (AppendStmt *) parseTree);
break;
case T_DeleteStmt:
result = transformDeleteStmt(pstate, (DeleteStmt *) parseTree);
break;
case T_ReplaceStmt:
result = transformUpdateStmt(pstate, (ReplaceStmt *) parseTree);
break;
case T_CursorStmt:
result = transformCursorStmt(pstate, (CursorStmt *) parseTree);
break;
case T_RetrieveStmt:
result = transformSelectStmt(pstate, (RetrieveStmt *) parseTree);
break;
default:
/*
* other statments don't require any transformation-- just
* return the original parsetree
*/
result = makeNode(Query);
result->commandType = CMD_UTILITY;
result->utilityStmt = (Node *) parseTree;
break;
}
return result;
}
/*
* transformDeleteStmt -
* transforms a Delete Statement
*/
static Query *
transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
{
Query *qry = makeNode(Query);
qry->commandType = CMD_DELETE;
/* set up a range table */
makeRangeTable(pstate, stmt->relname, NULL);
qry->uniqueFlag = NULL;
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause);
qry->rtable = pstate->p_rtable;
qry->resultRelation = refnameRangeTablePosn(pstate->p_rtable, stmt->relname);
/* make sure we don't have aggregates in the where clause */
if (pstate->p_numAgg > 0)
parseCheckAggregates(pstate, qry);
return (Query *) qry;
}
/*
* transformInsertStmt -
* transform an Insert Statement
*/
static Query *
transformInsertStmt(ParseState *pstate, AppendStmt *stmt)
{
Query *qry = makeNode(Query); /* make a new query tree */
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List *icolumns;
qry->commandType = CMD_INSERT;
pstate->p_is_insert = true;
/* set up a range table */
makeRangeTable(pstate, stmt->relname, stmt->fromClause);
qry->uniqueFlag = NULL;
/* fix the target list */
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icolumns = pstate->p_insert_columns = makeTargetNames(pstate, stmt->cols);
qry->targetList = transformTargetList(pstate, stmt->targetList);
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/* DEFAULT handling */
if (length(qry->targetList) < pstate->p_target_relation->rd_att->natts &&
pstate->p_target_relation->rd_att->constr &&
pstate->p_target_relation->rd_att->constr->num_defval > 0)
{
AttributeTupleForm *att = pstate->p_target_relation->rd_att->attrs;
AttrDefault *defval = pstate->p_target_relation->rd_att->constr->defval;
int ndef = pstate->p_target_relation->rd_att->constr->num_defval;
/*
* if stmt->cols == NIL then makeTargetNames returns list of all
* attrs: have to shorter icolumns list...
*/
if (stmt->cols == NIL)
{
List *extrl;
int i = length(qry->targetList);
foreach (extrl, icolumns)
{
if (--i <= 0)
break;
}
freeList (lnext(extrl));
lnext(extrl) = NIL;
}
while (ndef-- > 0)
{
List *tl;
Ident *id;
TargetEntry *te;
foreach (tl, icolumns)
{
id = (Ident *) lfirst(tl);
if (!namestrcmp(&(att[defval[ndef].adnum - 1]->attname), id->name))
break;
}
if (tl != NIL) /* something given for this attr */
continue;
/*
* Nothing given for this attr with DEFAULT expr, so
* add new TargetEntry to qry->targetList.
* Note, that we set resno to defval[ndef].adnum:
* it's what transformTargetList()->make_targetlist_expr()
* does for INSERT ... SELECT. But for INSERT ... VALUES
* pstate->p_last_resno is used. It doesn't matter for
* "normal" using (planner creates proper target list
* in preptlist.c), but may break RULEs in some way.
* It seems better to create proper target list here...
*/
te = makeNode(TargetEntry);
te->resdom = makeResdom(defval[ndef].adnum,
att[defval[ndef].adnum - 1]->atttypid,
att[defval[ndef].adnum - 1]->attlen,
pstrdup(nameout(&(att[defval[ndef].adnum - 1]->attname))),
0, 0, 0);
te->fjoin = NULL;
te->expr = (Node *) stringToNode(defval[ndef].adbin);
qry->targetList = lappend (qry->targetList, te);
}
}
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause);
/* now the range table will not change */
qry->rtable = pstate->p_rtable;
qry->resultRelation = refnameRangeTablePosn(pstate->p_rtable, stmt->relname);
if (pstate->p_numAgg > 0)
finalizeAggregates(pstate, qry);
return (Query *) qry;
}
/* makeTableName()
* Create a table name from a list of fields.
*/
static char *
makeTableName(void *elem,...);
static char *
makeTableName(void *elem,...)
{
va_list args;
char *name;
char buf[NAMEDATALEN+1];
strcpy(buf,"");
va_start(args,elem);
name = elem;
while (name != NULL)
{
/* not enough room for next part? then return nothing */
if ((strlen(buf)+strlen(name)) >= (sizeof(buf)-1))
return (NULL);
if (strlen(buf) > 0) strcat(buf,"_");
strcat(buf,name);
name = va_arg(args,void *);
}
va_end(args);
name = palloc(strlen(buf)+1);
strcpy(name,buf);
return (name);
} /* makeTableName() */
/*
* transformCreateStmt -
* transforms the "create table" statement
* SQL92 allows constraints to be scattered all over, so thumb through
* the columns and collect all constraints into one place.
* If there are any implied indices (e.g. UNIQUE or PRIMARY KEY)
* then expand those into multiple IndexStmt blocks.
* - thomas 1997-12-02
*/
static Query *
transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
{
Query *q;
List *elements;
Node *element;
List *columns;
List *dlist;
ColumnDef *column;
List *constraints, *clist;
Constraint *constraint;
List *keys;
Ident *key;
List *ilist;
IndexStmt *index;
IndexElem *iparam;
q = makeNode(Query);
q->commandType = CMD_UTILITY;
elements = stmt->tableElts;
constraints = stmt->constraints;
columns = NIL;
dlist = NIL;
while (elements != NIL)
{
element = lfirst(elements);
switch (nodeTag(element))
{
case T_ColumnDef:
column = (ColumnDef *) element;
#if PARSEDEBUG
printf("transformCreateStmt- found column %s\n",column->colname);
#endif
columns = lappend(columns,column);
if (column->constraints != NIL)
{
#if PARSEDEBUG
printf("transformCreateStmt- found constraint(s) on column %s\n",column->colname);
#endif
clist = column->constraints;
while (clist != NIL)
{
constraint = lfirst(clist);
switch (constraint->contype)
{
case CONSTR_NOTNULL:
#if PARSEDEBUG
printf("transformCreateStmt- found NOT NULL constraint on column %s\n",column->colname);
#endif
if (column->is_not_null)
elog(WARN,"CREATE TABLE/NOT NULL already specified"
" for %s.%s", stmt->relname, column->colname);
column->is_not_null = TRUE;
break;
case CONSTR_DEFAULT:
#if PARSEDEBUG
printf("transformCreateStmt- found DEFAULT clause on column %s\n",column->colname);
#endif
if (column->defval != NULL)
elog(WARN,"CREATE TABLE/DEFAULT multiple values specified"
" for %s.%s", stmt->relname, column->colname);
column->defval = constraint->def;
break;
case CONSTR_PRIMARY:
#if PARSEDEBUG
printf("transformCreateStmt- found PRIMARY KEY clause on column %s\n",column->colname);
#endif
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, "pkey", NULL);
if (constraint->keys == NIL)
constraint->keys = lappend(constraint->keys, column);
dlist = lappend(dlist, constraint);
break;
case CONSTR_UNIQUE:
#if PARSEDEBUG
printf("transformCreateStmt- found UNIQUE clause on column %s\n",column->colname);
#endif
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, column->colname, "key", NULL);
if (constraint->keys == NIL)
constraint->keys = lappend(constraint->keys, column);
dlist = lappend(dlist, constraint);
break;
case CONSTR_CHECK:
#if PARSEDEBUG
printf("transformCreateStmt- found CHECK clause on column %s\n",column->colname);
#endif
constraints = lappend(constraints, constraint);
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, ".", column->colname, NULL);
break;
default:
elog(WARN,"parser: internal error; unrecognized constraint",NULL);
break;
}
clist = lnext(clist);
}
}
break;
case T_Constraint:
constraint = (Constraint *) element;
#if PARSEDEBUG
printf("transformCreateStmt- found constraint %s\n", ((constraint->name != NULL)? constraint->name: "(unknown)"));
#endif
switch (constraint->contype)
{
case CONSTR_PRIMARY:
#if PARSEDEBUG
printf("transformCreateStmt- found PRIMARY KEY clause\n");
#endif
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, "pkey", NULL);
dlist = lappend(dlist, constraint);
break;
case CONSTR_UNIQUE:
#if PARSEDEBUG
printf("transformCreateStmt- found UNIQUE clause\n");
#endif
#if FALSE
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, "key", NULL);
#endif
dlist = lappend(dlist, constraint);
break;
case CONSTR_CHECK:
#if PARSEDEBUG
printf("transformCreateStmt- found CHECK clause\n");
#endif
constraints = lappend(constraints, constraint);
break;
case CONSTR_NOTNULL:
case CONSTR_DEFAULT:
elog(WARN,"parser: internal error; illegal context for constraint",NULL);
break;
default:
elog(WARN,"parser: internal error; unrecognized constraint",NULL);
break;
}
break;
default:
elog(WARN,"parser: internal error; unrecognized node",NULL);
}
elements = lnext(elements);
}
stmt->tableElts = columns;
stmt->constraints = constraints;
/* Now run through the "deferred list" to complete the query transformation.
* For PRIMARY KEYs, mark each column as NOT NULL and create an index.
* For UNIQUE, create an index as for PRIMARY KEYS, but do not insist on NOT NULL.
*
* Note that this code does not currently look for all possible redundant cases
* and either ignore or stop with warning. The create will fail later when
* names for indices turn out to be redundant, or a user might just find
* extra useless indices which might kill performance. - thomas 1997-12-04
*/
ilist = NIL;
while (dlist != NIL)
{
constraint = lfirst(dlist);
if (nodeTag(constraint) != T_Constraint)
elog(WARN,"parser: internal error; unrecognized deferred node",NULL);
if ((constraint->contype != CONSTR_PRIMARY)
&& (constraint->contype != CONSTR_UNIQUE))
elog(WARN,"parser: internal error; illegal deferred constraint",NULL);
#if PARSEDEBUG
printf("transformCreateStmt- found deferred constraint %s\n",
((constraint->name != NULL)? constraint->name: "(unknown)"));
#endif
#if PARSEDEBUG
printf("transformCreateStmt- found deferred %s clause\n",
(constraint->contype == CONSTR_PRIMARY? "PRIMARY KEY": "UNIQUE"));
#endif
index = makeNode(IndexStmt);
ilist = lappend(ilist, index);
index->unique = TRUE;
if (constraint->name != NULL)
index->idxname = constraint->name;
else if (constraint->contype == CONSTR_PRIMARY)
index->idxname = makeTableName(stmt->relname, "pkey", NULL);
else
index->idxname = NULL;
index->relname = stmt->relname;
index->accessMethod = "btree";
index->indexParams = NIL;
index->withClause = NIL;
index->whereClause = NULL;
keys = constraint->keys;
while (keys != NIL)
{
key = lfirst(keys);
#if PARSEDEBUG
printf("transformCreateStmt- check key %s for column match\n", key->name);
#endif
columns = stmt->tableElts;
column = NULL;
while (columns != NIL)
{
column = lfirst(columns);
#if PARSEDEBUG
printf("transformCreateStmt- check column %s for key match\n", column->colname);
#endif
if (strcasecmp(column->colname,key->name) == 0) break;
else column = NULL;
columns = lnext(columns);
}
if (column == NULL)
elog(WARN,"parser: column '%s' in key does not exist",key->name);
if (constraint->contype == CONSTR_PRIMARY)
{
#if PARSEDEBUG
printf("transformCreateStmt- mark column %s as NOT NULL\n", column->colname);
#endif
column->is_not_null = TRUE;
}
iparam = makeNode(IndexElem);
iparam->name = strcpy(palloc(strlen(column->colname)+1), column->colname);
iparam->args = NIL;
iparam->class = NULL;
iparam->tname = NULL;
index->indexParams = lappend(index->indexParams, iparam);
if (index->idxname == NULL)
index->idxname = makeTableName(stmt->relname, iparam->name, "key", NULL);
keys = lnext(keys);
}
if (index->idxname == NULL)
elog(WARN,"parser: unable to construct implicit index for table %s"
"; name too long", stmt->relname);
dlist = lnext(dlist);
}
q->utilityStmt = (Node *) stmt;
extras = ilist;
return q;
} /* transformCreateStmt() */
/*
* transformIndexStmt -
* transforms the qualification of the index statement
*/
static Query *
transformIndexStmt(ParseState *pstate, IndexStmt *stmt)
{
Query *q;
q = makeNode(Query);
q->commandType = CMD_UTILITY;
/* take care of the where clause */
stmt->whereClause = transformWhereClause(pstate, stmt->whereClause);
stmt->rangetable = pstate->p_rtable;
q->utilityStmt = (Node *) stmt;
return q;
}
/*
* transformExtendStmt -
* transform the qualifications of the Extend Index Statement
*
*/
static Query *
transformExtendStmt(ParseState *pstate, ExtendStmt *stmt)
{
Query *q;
q = makeNode(Query);
q->commandType = CMD_UTILITY;
/* take care of the where clause */
stmt->whereClause = transformWhereClause(pstate, stmt->whereClause);
stmt->rangetable = pstate->p_rtable;
q->utilityStmt = (Node *) stmt;
return q;
}
/*
* transformRuleStmt -
* transform a Create Rule Statement. The actions is a list of parse
* trees which is transformed into a list of query trees.
*/
static Query *
transformRuleStmt(ParseState *pstate, RuleStmt *stmt)
{
Query *q;
List *actions;
q = makeNode(Query);
q->commandType = CMD_UTILITY;
actions = stmt->actions;
/*
* transform each statment, like parse_analyze()
*/
while (actions != NIL)
{
/*
* NOTE: 'CURRENT' must always have a varno equal to 1 and 'NEW'
* equal to 2.
*/
addRangeTableEntry(pstate, stmt->object->relname, "*CURRENT*",
FALSE, FALSE);
addRangeTableEntry(pstate, stmt->object->relname, "*NEW*",
FALSE, FALSE);
pstate->p_last_resno = 1;
pstate->p_is_rule = true; /* for expand all */
pstate->p_numAgg = 0;
pstate->p_aggs = NULL;
lfirst(actions) = transformStmt(pstate, lfirst(actions));
actions = lnext(actions);
}
/* take care of the where clause */
stmt->whereClause = transformWhereClause(pstate, stmt->whereClause);
q->utilityStmt = (Node *) stmt;
return q;
}
/*
* transformSelectStmt -
* transforms a Select Statement
*
*/
static Query *
transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt)
{
Query *qry = makeNode(Query);
qry->commandType = CMD_SELECT;
/* set up a range table */
makeRangeTable(pstate, NULL, stmt->fromClause);
qry->uniqueFlag = stmt->unique;
qry->into = stmt->into;
qry->isPortal = FALSE;
/* fix the target list */
qry->targetList = transformTargetList(pstate, stmt->targetList);
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause);
/* check subselect clause */
if (stmt->selectClause)
elog(NOTICE, "UNION not yet supported; using first SELECT only", NULL);
/* check subselect clause */
if (stmt->havingClause)
elog(NOTICE, "HAVING not yet supported; ignore clause", NULL);
/* fix order clause */
qry->sortClause = transformSortClause(pstate,
stmt->sortClause,
qry->targetList,
qry->uniqueFlag);
/* fix group by clause */
qry->groupClause = transformGroupClause(pstate,
stmt->groupClause,
qry->targetList);
qry->rtable = pstate->p_rtable;
if (pstate->p_numAgg > 0)
finalizeAggregates(pstate, qry);
return (Query *) qry;
}
/*
* transformUpdateStmt -
* transforms an update statement
*
*/
static Query *
transformUpdateStmt(ParseState *pstate, ReplaceStmt *stmt)
{
Query *qry = makeNode(Query);
qry->commandType = CMD_UPDATE;
pstate->p_is_update = true;
/*
* the FROM clause is non-standard SQL syntax. We used to be able to
* do this with REPLACE in POSTQUEL so we keep the feature.
*/
makeRangeTable(pstate, stmt->relname, stmt->fromClause);
/* fix the target list */
qry->targetList = transformTargetList(pstate, stmt->targetList);
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause);
qry->rtable = pstate->p_rtable;
qry->resultRelation = refnameRangeTablePosn(pstate->p_rtable, stmt->relname);
/* make sure we don't have aggregates in the where clause */
if (pstate->p_numAgg > 0)
parseCheckAggregates(pstate, qry);
return (Query *) qry;
}
/*
* transformCursorStmt -
* transform a Create Cursor Statement
*
*/
static Query *
transformCursorStmt(ParseState *pstate, CursorStmt *stmt)
{
Query *qry = makeNode(Query);
/*
* in the old days, a cursor statement is a 'retrieve into portal'; If
* you change the following, make sure you also go through the code in
* various places that tests the kind of operation.
*/
qry->commandType = CMD_SELECT;
/* set up a range table */
makeRangeTable(pstate, NULL, stmt->fromClause);
qry->uniqueFlag = stmt->unique;
qry->into = stmt->portalname;
qry->isPortal = TRUE;
qry->isBinary = stmt->binary; /* internal portal */
/* fix the target list */
qry->targetList = transformTargetList(pstate, stmt->targetList);
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause);
/* fix order clause */
qry->sortClause = transformSortClause(pstate,
stmt->sortClause,
qry->targetList,
qry->uniqueFlag);
/* fix group by clause */
qry->groupClause = transformGroupClause(pstate,
stmt->groupClause,
qry->targetList);
qry->rtable = pstate->p_rtable;
if (pstate->p_numAgg > 0)
finalizeAggregates(pstate, qry);
return (Query *) qry;
}