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Re-order pg_attribute columns to eliminate some padding space.

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Now that attcompression is just a char, there's a lot of wasted
padding space after it.  Move it into the group of char-wide
columns to save a net of 4 bytes per pg_attribute entry.  While
we're at it, swap the order of attstorage and attalign to make for
a more logical grouping of these columns.

Also re-order actions in related code to match the new field ordering.

This patch also fixes one outright bug: equalTupleDescs() failed to
compare attcompression.  That could, for example, cause relcache
reload to fail to adopt a new value following a change.

Michael Paquier and Tom Lane, per a gripe from Andres Freund.

Discussion: https://postgr.es/m/20210517204803.iyk5wwvwgtjcmc5w@alap3.anarazel.de
This commit is contained in:
Tom Lane
2021-05-23 12:12:09 -04:00
parent bc2a389efb
commit f5024d8d7b
11 changed files with 80 additions and 74 deletions
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13
src/backend/bootstrap/bootstrap.c
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@ -699,8 +699,8 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
attrtypes[attnum]->atttypid = Ap->am_oid;
attrtypes[attnum]->attlen = Ap->am_typ.typlen;
attrtypes[attnum]->attbyval = Ap->am_typ.typbyval;
attrtypes[attnum]->attstorage = Ap->am_typ.typstorage;
attrtypes[attnum]->attalign = Ap->am_typ.typalign;
attrtypes[attnum]->attstorage = Ap->am_typ.typstorage;
attrtypes[attnum]->attcollation = Ap->am_typ.typcollation;
/* if an array type, assume 1-dimensional attribute */
if (Ap->am_typ.typelem != InvalidOid && Ap->am_typ.typlen < 0)
@ -713,8 +713,8 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
attrtypes[attnum]->atttypid = TypInfo[typeoid].oid;
attrtypes[attnum]->attlen = TypInfo[typeoid].len;
attrtypes[attnum]->attbyval = TypInfo[typeoid].byval;
attrtypes[attnum]->attstorage = TypInfo[typeoid].storage;
attrtypes[attnum]->attalign = TypInfo[typeoid].align;
attrtypes[attnum]->attstorage = TypInfo[typeoid].storage;
attrtypes[attnum]->attcollation = TypInfo[typeoid].collation;
/* if an array type, assume 1-dimensional attribute */
if (TypInfo[typeoid].elem != InvalidOid &&
@ -724,6 +724,11 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
attrtypes[attnum]->attndims = 0;
}
if (IsStorageCompressible(attrtypes[attnum]->attstorage))
attrtypes[attnum]->attcompression = GetDefaultToastCompression();
else
attrtypes[attnum]->attcompression = InvalidCompressionMethod;
/*
* If a system catalog column is collation-aware, force it to use C
* collation, so that its behavior is independent of the database's
@ -737,10 +742,6 @@ DefineAttr(char *name, char *type, int attnum, int nullness)
attrtypes[attnum]->attcacheoff = -1;
attrtypes[attnum]->atttypmod = -1;
attrtypes[attnum]->attislocal = true;
if (IsStorageCompressible(attrtypes[attnum]->attstorage))
attrtypes[attnum]->attcompression = GetDefaultToastCompression();
else
attrtypes[attnum]->attcompression = InvalidCompressionMethod;
if (nullness == BOOTCOL_NULL_FORCE_NOT_NULL)
{