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| author | Peter Eisentraut <peter@eisentraut.org> | 2019-03-30 08:13:09 +0100 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2019-03-30 08:15:57 +0100 |
| commit | fc22b6623b6b3bab3cb057ccd282c2bfad1a0b30 (patch) | |
| tree | cda5092955ece5d547d5517ed56a3d480f199d25 /src/backend/access | |
| parent | 6b8b5364ddd0e4d882562615c6b6c28638ade9f2 (diff) | |
| download | postgresql-fc22b6623b6b3bab3cb057ccd282c2bfad1a0b30.tar.gz postgresql-fc22b6623b6b3bab3cb057ccd282c2bfad1a0b30.zip | |
Generated columns
This is an SQL-standard feature that allows creating columns that are
computed from expressions rather than assigned, similar to a view or
materialized view but on a column basis.
This implements one kind of generated column: stored (computed on
write). Another kind, virtual (computed on read), is planned for the
future, and some room is left for it.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/b151f851-4019-bdb1-699e-ebab07d2f40a@2ndquadrant.com
Diffstat (limited to 'src/backend/access')
| -rw-r--r-- | src/backend/access/common/tupdesc.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c index 0158950a432..6bc4e4c0360 100644 --- a/src/backend/access/common/tupdesc.c +++ b/src/backend/access/common/tupdesc.c @@ -131,6 +131,7 @@ CreateTupleDescCopy(TupleDesc tupdesc) att->atthasdef = false; att->atthasmissing = false; att->attidentity = '\0'; + att->attgenerated = '\0'; } /* We can copy the tuple type identification, too */ @@ -165,6 +166,7 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc) TupleConstr *cpy = (TupleConstr *) palloc0(sizeof(TupleConstr)); cpy->has_not_null = constr->has_not_null; + cpy->has_generated_stored = constr->has_generated_stored; if ((cpy->num_defval = constr->num_defval) > 0) { @@ -247,6 +249,7 @@ TupleDescCopy(TupleDesc dst, TupleDesc src) att->atthasdef = false; att->atthasmissing = false; att->attidentity = '\0'; + att->attgenerated = '\0'; } dst->constr = NULL; @@ -300,6 +303,7 @@ TupleDescCopyEntry(TupleDesc dst, AttrNumber dstAttno, dstAtt->atthasdef = false; dstAtt->atthasmissing = false; dstAtt->attidentity = '\0'; + dstAtt->attgenerated = '\0'; } /* @@ -456,6 +460,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) return false; if (attr1->attidentity != attr2->attidentity) return false; + if (attr1->attgenerated != attr2->attgenerated) + return false; if (attr1->attisdropped != attr2->attisdropped) return false; if (attr1->attislocal != attr2->attislocal) @@ -476,6 +482,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) return false; if (constr1->has_not_null != constr2->has_not_null) return false; + if (constr1->has_generated_stored != constr2->has_generated_stored) + return false; n = constr1->num_defval; if (n != (int) constr2->num_defval) return false; @@ -638,6 +646,7 @@ TupleDescInitEntry(TupleDesc desc, att->atthasdef = false; att->atthasmissing = false; att->attidentity = '\0'; + att->attgenerated = '\0'; att->attisdropped = false; att->attislocal = true; att->attinhcount = 0; @@ -697,6 +706,7 @@ TupleDescInitBuiltinEntry(TupleDesc desc, att->atthasdef = false; att->atthasmissing = false; att->attidentity = '\0'; + att->attgenerated = '\0'; att->attisdropped = false; att->attislocal = true; att->attinhcount = 0; @@ -853,6 +863,7 @@ BuildDescForRelation(List *schema) TupleConstr *constr = (TupleConstr *) palloc0(sizeof(TupleConstr)); constr->has_not_null = true; + constr->has_generated_stored = false; constr->defval = NULL; constr->missing = NULL; constr->num_defval = 0; |