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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-04-14 22:34:48 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-04-14 22:34:48 +0000 |
| commit | 8e14408028e31a3dad872a0735a435ba10017ae6 (patch) | |
| tree | 99fbb5bd8b2d8487ae0e1b0a5deb6777cd4d3f60 | |
| parent | 0453a997af76a36530200dbf8403e70849ff4c0b (diff) | |
| download | postgresql-8e14408028e31a3dad872a0735a435ba10017ae6.tar.gz postgresql-8e14408028e31a3dad872a0735a435ba10017ae6.zip | |
Make equalTupleDescs() compare attlen/attbyval/attalign rather than
assuming comparison of atttypid is sufficient. In a dropped column
atttypid will be 0, and we'd better check the physical-storage data
to make sure the tupdescs are physically compatible.
I do not believe there is a real risk before 8.0, since before that
we only used this routine to compare successive states of the tupdesc
for a particular relation. But 8.0's typcache.c might be comparing
arbitrary tupdescs so we'd better play it safer.
| -rw-r--r-- | src/backend/access/common/tupdesc.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c index fac8551dfd6..fedc7ec4894 100644 --- a/src/backend/access/common/tupdesc.c +++ b/src/backend/access/common/tupdesc.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/common/tupdesc.c,v 1.110 2005/03/31 22:46:04 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/common/tupdesc.c,v 1.111 2005/04/14 22:34:48 tgl Exp $ * * NOTES * some of the executor utility code such as "ExecTypeFromTL" should be @@ -274,10 +274,15 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) /* * We do not need to check every single field here: we can - * disregard attrelid, attnum (it was used to place the row in the - * attrs array) and everything derived from the column datatype. - * Also, attcacheoff must NOT be checked since it's possibly not - * set in both copies. + * disregard attrelid and attnum (which were used to place the row + * in the attrs array in the first place). It might look like we + * could dispense with checking attlen/attbyval/attalign, since these + * are derived from atttypid; but in the case of dropped columns + * we must check them (since atttypid will be zero for all dropped + * columns) and in general it seems safer to check them always. + * + * attcacheoff must NOT be checked since it's possibly not set + * in both copies. */ if (strcmp(NameStr(attr1->attname), NameStr(attr2->attname)) != 0) return false; @@ -285,12 +290,18 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) return false; if (attr1->attstattarget != attr2->attstattarget) return false; + if (attr1->attlen != attr2->attlen) + return false; if (attr1->attndims != attr2->attndims) return false; if (attr1->atttypmod != attr2->atttypmod) return false; + if (attr1->attbyval != attr2->attbyval) + return false; if (attr1->attstorage != attr2->attstorage) return false; + if (attr1->attalign != attr2->attalign) + return false; if (attr1->attnotnull != attr2->attnotnull) return false; if (attr1->atthasdef != attr2->atthasdef) |