diff options
| author | Tom Lane | 2004-06-05 01:55:05 +0000 |
|---|---|---|
| committer | Tom Lane | 2004-06-05 01:55:05 +0000 |
| commit | ae93e5fd6e8a7e2321e87d23165d9d7660cde598 (patch) | |
| tree | a8e22c4835283c61e137285ba2dabfe3feead1a9 /src/include/access | |
| parent | 8f2ea8b7b53a02078ba0393e6892ac5356a3631e (diff) | |
Make the world very nearly safe for composite-type columns in tables.
1. Solve the problem of not having TOAST references hiding inside composite
values by establishing the rule that toasting only goes one level deep:
a tuple can contain toasted fields, but a composite-type datum that is
to be inserted into a tuple cannot. Enforcing this in heap_formtuple
is relatively cheap and it avoids a large increase in the cost of running
the tuptoaster during final storage of a row.
2. Fix some interesting problems in expansion of inherited queries that
reference whole-row variables. We never really did this correctly before,
but it's now relatively painless to solve by expanding the parent's
whole-row Var into a RowExpr() selecting the proper columns from the
child.
If you dike out the preventive check in CheckAttributeType(),
composite-type columns now seem to actually work. However, we surely
cannot ship them like this --- without I/O for composite types, you
can't get pg_dump to dump tables containing them. So a little more
work still to do.
Diffstat (limited to 'src/include/access')
| -rw-r--r-- | src/include/access/tuptoaster.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/src/include/access/tuptoaster.h b/src/include/access/tuptoaster.h index 2e2fcc91543..3332e9ab62b 100644 --- a/src/include/access/tuptoaster.h +++ b/src/include/access/tuptoaster.h @@ -6,7 +6,7 @@ * * Copyright (c) 2000-2003, PostgreSQL Global Development Group * - * $PostgreSQL: pgsql/src/include/access/tuptoaster.h,v 1.17 2003/11/29 22:40:55 pgsql Exp $ + * $PostgreSQL: pgsql/src/include/access/tuptoaster.h,v 1.18 2004/06/05 01:55:05 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -111,6 +111,18 @@ extern varattrib *heap_tuple_untoast_attr_slice(varattrib *attr, int32 slicelength); /* ---------- + * toast_flatten_tuple_attribute - + * + * If a Datum is of composite type, "flatten" it to contain no toasted fields. + * This must be invoked on any potentially-composite field that is to be + * inserted into a tuple. Doing this preserves the invariant that toasting + * goes only one level deep in a tuple. + * ---------- + */ +extern Datum toast_flatten_tuple_attribute(Datum value, + Oid typeId, int32 typeMod); + +/* ---------- * toast_compress_datum - * * Create a compressed version of a varlena datum, if possible |