diff options
Diffstat (limited to 'src/bin/pg_dump/common.c')
| -rw-r--r-- | src/bin/pg_dump/common.c | 43 |
1 files changed, 29 insertions, 14 deletions
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c index 409bc9b8e2..a43f2e5553 100644 --- a/src/bin/pg_dump/common.c +++ b/src/bin/pg_dump/common.c @@ -452,14 +452,15 @@ flagInhIndexes(Archive *fout, TableInfo tblinfo[], int numTables) * that we'll correctly emit the necessary DEFAULT NULL clause; otherwise * the backend will apply an inherited default to the column. * - * - Detect child columns that have a generation expression when their parents - * also have one. Generation expressions are always inherited, so there is - * no need to set them again in child tables, and there is no syntax for it - * either. Exceptions: If it's a partition or we are in binary upgrade - * mode, we dump them because in those cases inherited tables are recreated - * standalone first and then reattached to the parent. (See also the logic - * in dumpTableSchema().) In that situation, the generation expressions - * must match the parent, enforced by ALTER TABLE. + * - Detect child columns that have a generation expression and all their + * parents also have the same generation expression, and if so suppress the + * child's expression. The child will inherit the generation expression + * automatically, so there's no need to dump it. This improves the dump's + * compatibility with pre-v16 servers, which didn't allow the child's + * expression to be given explicitly. Exceptions: If it's a partition or + * we are in binary upgrade mode, we dump such expressions anyway because + * in those cases inherited tables are recreated standalone first and then + * reattached to the parent. (See also the logic in dumpTableSchema().) * * modifies tblinfo */ @@ -497,7 +498,8 @@ flagInhAttrs(DumpOptions *dopt, TableInfo *tblinfo, int numTables) { bool foundNotNull; /* Attr was NOT NULL in a parent */ bool foundDefault; /* Found a default in a parent */ - bool foundGenerated; /* Found a generated in a parent */ + bool foundSameGenerated; /* Found matching GENERATED */ + bool foundDiffGenerated; /* Found non-matching GENERATED */ /* no point in examining dropped columns */ if (tbinfo->attisdropped[j]) @@ -505,7 +507,8 @@ flagInhAttrs(DumpOptions *dopt, TableInfo *tblinfo, int numTables) foundNotNull = false; foundDefault = false; - foundGenerated = false; + foundSameGenerated = false; + foundDiffGenerated = false; for (k = 0; k < numParents; k++) { TableInfo *parent = parents[k]; @@ -517,8 +520,19 @@ flagInhAttrs(DumpOptions *dopt, TableInfo *tblinfo, int numTables) if (inhAttrInd >= 0) { foundNotNull |= parent->notnull[inhAttrInd]; - foundDefault |= (parent->attrdefs[inhAttrInd] != NULL && !parent->attgenerated[inhAttrInd]); - foundGenerated |= parent->attgenerated[inhAttrInd]; + foundDefault |= (parent->attrdefs[inhAttrInd] != NULL && + !parent->attgenerated[inhAttrInd]); + if (parent->attgenerated[inhAttrInd]) + { + /* these pointer nullness checks are just paranoia */ + if (parent->attrdefs[inhAttrInd] != NULL && + tbinfo->attrdefs[j] != NULL && + strcmp(parent->attrdefs[inhAttrInd]->adef_expr, + tbinfo->attrdefs[j]->adef_expr) == 0) + foundSameGenerated = true; + else + foundDiffGenerated = true; + } } } @@ -561,8 +575,9 @@ flagInhAttrs(DumpOptions *dopt, TableInfo *tblinfo, int numTables) tbinfo->attrdefs[j] = attrDef; } - /* Remove generation expression from child */ - if (foundGenerated && !tbinfo->ispartition && !dopt->binary_upgrade) + /* Remove generation expression from child if possible */ + if (foundSameGenerated && !foundDiffGenerated && + !tbinfo->ispartition && !dopt->binary_upgrade) tbinfo->attrdefs[j] = NULL; } } |