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1 | 1 | /*------------------------------------------------------------------------- |
2 | 2 | * |
3 | 3 | * indexcmds.c |
4 | | - * POSTGRES define, extend and remove index code. |
| 4 | + * POSTGRES define and remove index code. |
5 | 5 | * |
6 | 6 | * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group |
7 | 7 | * Portions Copyright (c) 1994, Regents of the University of California |
8 | 8 | * |
9 | 9 | * |
10 | 10 | * IDENTIFICATION |
11 | | - * $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.52 2001/07/16 05:06:57 tgl Exp $ |
| 11 | + * $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.53 2001/07/17 21:53:01 tgl Exp $ |
12 | 12 | * |
13 | 13 | *------------------------------------------------------------------------- |
14 | 14 | */ |
|
39 | 39 | #include"parser/parse_type.h" |
40 | 40 | #include"utils/builtins.h" |
41 | 41 | #include"utils/fmgroids.h" |
| 42 | +#include"utils/lsyscache.h" |
42 | 43 | #include"utils/syscache.h" |
43 | 44 |
|
| 45 | + |
44 | 46 | #defineIsFuncIndex(ATTR_LIST) (((IndexElem*)lfirst(ATTR_LIST))->args != NIL) |
45 | 47 |
|
46 | 48 | /* non-export function prototypes */ |
@@ -232,10 +234,21 @@ CheckPredicate(List *predList, List *rangeTable, Oid baseRelOid) |
232 | 234 | elog(ERROR, |
233 | 235 | "Partial-index predicates may refer only to the base relation"); |
234 | 236 |
|
| 237 | +/* |
| 238 | + * We don't currently support generation of an actual query plan for a |
| 239 | + * predicate, only simple scalar expressions; hence these restrictions. |
| 240 | + */ |
235 | 241 | if (contain_subplans((Node*)predList)) |
236 | 242 | elog(ERROR,"Cannot use subselect in index predicate"); |
237 | 243 | if (contain_agg_clause((Node*)predList)) |
238 | 244 | elog(ERROR,"Cannot use aggregate in index predicate"); |
| 245 | + |
| 246 | +/* |
| 247 | + * A predicate using noncachable functions is probably wrong, for the |
| 248 | + * same reasons that we don't allow a functional index to use one. |
| 249 | + */ |
| 250 | +if (contain_noncachable_functions((Node*)predList)) |
| 251 | +elog(ERROR,"Cannot use non-cachable function in index predicate"); |
239 | 252 | } |
240 | 253 |
|
241 | 254 |
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@@ -308,6 +321,15 @@ FuncIndexArgs(IndexInfo *indexInfo, |
308 | 321 | "Index function must be binary-compatible with table datatype"); |
309 | 322 | } |
310 | 323 |
|
| 324 | +/* |
| 325 | + * Require that the function be marked cachable. Using a noncachable |
| 326 | + * function for a functional index is highly questionable, since if you |
| 327 | + * aren't going to get the same result for the same data every time, |
| 328 | + * it's not clear what the index entries mean at all. |
| 329 | + */ |
| 330 | +if (!func_iscachable(funcid)) |
| 331 | +elog(ERROR,"DefineIndex: index function must be marked iscachable"); |
| 332 | + |
311 | 333 | /* Process opclass, using func return type as default type */ |
312 | 334 |
|
313 | 335 | classOidP[0]=GetAttrOpClass(funcIndex,rettype, |
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