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Postgres FD Implementation
Commit ca234c3f authored by Tom Lane's avatar Tom Lane
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Instead of failing when the constructed name for a sequence, 

index, etc is too long, truncate until it fits.
parent 4cf595bf
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Showing with 92 additions and 85 deletions
src/backend/parser/analyze.c
View file @ ca234c3f
......@@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: analyze.c,v 1.109 1999/05/25 22:04:25 momjian Exp $
* $Id: analyze.c,v 1.110 1999/06/05 20:22:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -410,39 +410,79 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
}
/*
* makeTableName()
* Create a table name from a list of fields.
* makeObjectName()
*
* Create a name for an implicitly created index, sequence, constraint, etc.
*
* The parameters are: the original table name, the original field name, and
* a "type" string (such as "seq" or "pkey"). The field name and/or type
* can be NULL if not relevant.
*
* The result is a palloc'd string.
*
* The basic result we want is "name1_name2_type", omitting "_name2" or
* "_type" when those parameters are NULL. However, we must generate
* a name with less than NAMEDATALEN characters! So, we truncate one or
* both names if necessary to make a short-enough string. The type part
* is never truncated (so it had better be reasonably short).
*
* To reduce the probability of collisions, we might someday add more
* smarts to this routine, like including some "hash" characters computed
* from the truncated characters. Currently it seems best to keep it simple,
* so that the generated names are easily predictable by a person.
*/
static char *
makeTableName(void *elem,...)
makeObjectName(char *name1, char *name2, char *typename)
{
va_list args;
char *name;
char buf[NAMEDATALEN + 1];
buf[0] = '\0';
va_start(args, elem);
name = elem;
while (name != NULL)
int overhead = 0; /* chars needed for type and underscores */
int availchars; /* chars available for name(s) */
int name1chars; /* chars allocated to name1 */
int name2chars; /* chars allocated to name2 */
int ndx;
name1chars = strlen(name1);
if (name2)
{
/* not enough room for next part? then return nothing */
if ((strlen(buf) + strlen(name)) >= (sizeof(buf) - 1))
return NULL;
name2chars = strlen(name2);
overhead++; /* allow for separating underscore */
}
else
name2chars = 0;
if (typename)
overhead += strlen(typename) + 1;
if (strlen(buf) > 0)
strcat(buf, "_");
strcat(buf, name);
availchars = NAMEDATALEN-1 - overhead;
name = va_arg(args, void *);
/* If we must truncate, preferentially truncate the longer name.
* This logic could be expressed without a loop, but it's simple and
* obvious as a loop.
*/
while (name1chars + name2chars > availchars)
{
if (name1chars > name2chars)
name1chars--;
else
name2chars--;
}
va_end(args);
name = palloc(strlen(buf) + 1);
strcpy(name, buf);
/* Now construct the string using the chosen lengths */
name = palloc(name1chars + name2chars + overhead + 1);
strncpy(name, name1, name1chars);
ndx = name1chars;
if (name2)
{
name[ndx++] = '_';
strncpy(name+ndx, name2, name2chars);
ndx += name2chars;
}
if (typename)
{
name[ndx++] = '_';
strcpy(name+ndx, typename);
}
else
name[ndx] = '\0';
return name;
}
......@@ -453,26 +493,24 @@ CreateIndexName(char *table_name, char *column_name, char *label, List *indices)
int pass = 0;
char *iname = NULL;
List *ilist;
IndexStmt *index;
char name2[NAMEDATALEN + 1];
char typename[NAMEDATALEN];
/* The type name for makeObjectName is label, or labelN if that's
* necessary to prevent collisions among multiple indexes for the same
* table. Note there is no check for collisions with already-existing
* indexes; this ought to be rethought someday.
*/
strcpy(typename, label);
/* use working storage, since we might be trying several possibilities */
strcpy(name2, column_name);
while (iname == NULL)
for (;;)
{
iname = makeTableName(table_name, name2, label, NULL);
/* unable to make a name at all? then quit */
if (iname == NULL)
break;
iname = makeObjectName(table_name, column_name, typename);
ilist = indices;
while (ilist != NIL)
foreach(ilist, indices)
{
index = lfirst(ilist);
IndexStmt *index = lfirst(ilist);
if (strcasecmp(iname, index->idxname) == 0)
break;
ilist = lnext(ilist);
}
/* ran through entire list? then no name conflict found so done */
if (ilist == NIL)
......@@ -480,9 +518,7 @@ CreateIndexName(char *table_name, char *column_name, char *label, List *indices)
/* the last one conflicted, so try a new name component */
pfree(iname);
iname = NULL;
pass++;
sprintf(name2, "%s_%d", column_name, (pass + 1));
sprintf(typename, "%s%d", label, ++pass);
}
return iname;
......@@ -542,12 +578,8 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
char *cstring;
CreateSeqStmt *sequence;
sname = makeTableName(stmt->relname, column->colname, "seq", NULL);
if (sname == NULL)
elog(ERROR, "CREATE TABLE/SERIAL implicit sequence name must be less than %d characters"
"\n\tSum of lengths of '%s' and '%s' must be less than %d",
NAMEDATALEN, stmt->relname, column->colname, (NAMEDATALEN - 5));
sname = makeObjectName(stmt->relname, column->colname,
"seq");
constraint = makeNode(Constraint);
constraint->contype = CONSTR_DEFAULT;
constraint->name = sname;
......@@ -562,11 +594,9 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
constraint = makeNode(Constraint);
constraint->contype = CONSTR_UNIQUE;
constraint->name = makeTableName(stmt->relname, column->colname, "key", NULL);
if (constraint->name == NULL)
elog(ERROR, "CREATE TABLE/SERIAL implicit index name must be less than %d characters"
"\n\tSum of lengths of '%s' and '%s' must be less than %d",
NAMEDATALEN, stmt->relname, column->colname, (NAMEDATALEN - 5));
constraint->name = makeObjectName(stmt->relname,
column->colname,
"key");
column->constraints = lappend(column->constraints, constraint);
sequence = makeNode(CreateSeqStmt);
......@@ -616,11 +646,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
case CONSTR_PRIMARY:
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, "pkey", NULL);
if (constraint->name == NULL)
elog(ERROR, "CREATE TABLE/PRIMARY KEY implicit index name must be less than %d characters"
"\n\tLength of '%s' must be less than %d",
NAMEDATALEN, stmt->relname, (NAMEDATALEN - 6));
constraint->name = makeObjectName(stmt->relname, NULL, "pkey");
if (constraint->keys == NIL)
constraint->keys = lappend(constraint->keys, column);
dlist = lappend(dlist, constraint);
......@@ -628,11 +654,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
case CONSTR_UNIQUE:
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, column->colname, "key", NULL);
if (constraint->name == NULL)
elog(ERROR, "CREATE TABLE/UNIQUE implicit index name must be less than %d characters"
"\n\tLength of '%s' must be less than %d",
NAMEDATALEN, stmt->relname, (NAMEDATALEN - 5));
constraint->name = makeObjectName(stmt->relname, column->colname, "key");
if (constraint->keys == NIL)
constraint->keys = lappend(constraint->keys, column);
dlist = lappend(dlist, constraint);
......@@ -641,11 +663,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
case CONSTR_CHECK:
constraints = lappend(constraints, constraint);
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, column->colname, NULL);
if (constraint->name == NULL)
elog(ERROR, "CREATE TABLE/CHECK implicit constraint name must be less than %d characters"
"\n\tSum of lengths of '%s' and '%s' must be less than %d",
NAMEDATALEN, stmt->relname, column->colname, (NAMEDATALEN - 1));
constraint->name = makeObjectName(stmt->relname, column->colname, NULL);
break;
default:
......@@ -663,11 +681,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
{
case CONSTR_PRIMARY:
if (constraint->name == NULL)
constraint->name = makeTableName(stmt->relname, "pkey", NULL);
if (constraint->name == NULL)
elog(ERROR, "CREATE TABLE/PRIMARY KEY implicit index name must be less than %d characters"
"\n\tLength of '%s' must be less than %d",
NAMEDATALEN, stmt->relname, (NAMEDATALEN - 5));
constraint->name = makeObjectName(stmt->relname, NULL, "pkey");
dlist = lappend(dlist, constraint);
break;
......@@ -728,15 +742,9 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
}
if (constraint->name != NULL)
index->idxname = constraint->name;
index->idxname = pstrdup(constraint->name);
else if (constraint->contype == CONSTR_PRIMARY)
{
index->idxname = makeTableName(stmt->relname, "pkey", NULL);
if (index->idxname == NULL)
elog(ERROR, "CREATE TABLE/PRIMARY KEY implicit index name must be less than %d characters"
"\n\tLength of '%s' must be less than %d",
NAMEDATALEN, stmt->relname, (NAMEDATALEN - 5));
}
index->idxname = makeObjectName(stmt->relname, NULL, "pkey");
else
index->idxname = NULL;
......@@ -767,7 +775,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
if (constraint->contype == CONSTR_PRIMARY)
column->is_not_null = TRUE;
iparam = makeNode(IndexElem);
iparam->name = strcpy(palloc(strlen(column->colname) + 1), column->colname);
iparam->name = pstrdup(column->colname);
iparam->args = NIL;
iparam->class = NULL;
iparam->typename = NULL;
......@@ -779,9 +787,8 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
keys = lnext(keys);
}
if (index->idxname == NULL)
elog(ERROR, "CREATE TABLE unable to construct implicit index for table '%s'"
"; name too long", stmt->relname);
if (index->idxname == NULL) /* should not happen */
elog(ERROR, "CREATE TABLE: failed to make implicit index name");
ilist = lappend(ilist, index);
dlist = lnext(dlist);
......
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