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Fix pg_dump for better handling of inherited columns.

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Revise pg_dump's handling of inherited columns, which was last looked at
seriously in 2001, to eliminate several misbehaviors associated with
inherited default expressions and NOT NULL flags.  In particular make sure
that a column is printed in a child table's CREATE TABLE command if and
only if it has attislocal = true; the former behavior would sometimes cause
a column to become marked attislocal when it was not so marked in the
source database.  Also, stop relying on textual comparison of default
expressions to decide if they're inherited; instead, don't use
default-expression inheritance at all, but just install the default
explicitly at each level of the hierarchy.  This fixes the
search-path-related misbehavior recently exhibited by Chester Young, and
also removes some dubious assumptions about the order in which ALTER TABLE
SET DEFAULT commands would be executed.

Back-patch to all supported branches.
This commit is contained in:
Tom Lane
2012-02-10 13:28:05 -05:00
parent d06e2d2005
commit 00bc96bd2b
4 changed files with 169 additions and 158 deletions
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148
src/bin/pg_dump/pg_dump.c
View File

@@ -5833,6 +5833,9 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
* attstattarget doesn't exist in 7.1. It does exist in 7.2, but
* we don't dump it because we can't tell whether it's been
* explicitly set or was just a default.
*
* attislocal doesn't exist before 7.3, either; in older databases
* we just assume that inherited columns had no local definition.
*/
appendPQExpBuffer(q, "SELECT a.attnum, a.attname, a.atttypmod, "
"-1 AS attstattarget, a.attstorage, "
@@ -5900,14 +5903,12 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
tbinfo->attlen = (int *) pg_malloc(ntups * sizeof(int));
tbinfo->attalign = (char *) pg_malloc(ntups * sizeof(char));
tbinfo->attislocal = (bool *) pg_malloc(ntups * sizeof(bool));
tbinfo->notnull = (bool *) pg_malloc(ntups * sizeof(bool));
tbinfo->attrdefs = (AttrDefInfo **) pg_malloc(ntups * sizeof(AttrDefInfo *));
tbinfo->attoptions = (char **) pg_malloc(ntups * sizeof(char *));
tbinfo->attcollation = (Oid *) pg_malloc(ntups * sizeof(Oid));
tbinfo->attfdwoptions = (char **) pg_malloc(ntups * sizeof(char *));
tbinfo->inhAttrs = (bool *) pg_malloc(ntups * sizeof(bool));
tbinfo->inhAttrDef = (bool *) pg_malloc(ntups * sizeof(bool));
tbinfo->notnull = (bool *) pg_malloc(ntups * sizeof(bool));
tbinfo->inhNotNull = (bool *) pg_malloc(ntups * sizeof(bool));
tbinfo->attrdefs = (AttrDefInfo **) pg_malloc(ntups * sizeof(AttrDefInfo *));
hasdefaults = false;
for (j = 0; j < ntups; j++)
@@ -5936,8 +5937,6 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
if (PQgetvalue(res, j, i_atthasdef)[0] == 't')
hasdefaults = true;
/* these flags will be set in flagInhAttrs() */
tbinfo->inhAttrs[j] = false;
tbinfo->inhAttrDef[j] = false;
tbinfo->inhNotNull[j] = false;
}
@@ -6000,12 +5999,28 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
{
int adnum;
adnum = atoi(PQgetvalue(res, j, 2));
if (adnum <= 0 || adnum > ntups)
{
write_msg(NULL, "invalid adnum value %d for table \"%s\"\n",
adnum, tbinfo->dobj.name);
exit_nicely();
}
/*
* dropped columns shouldn't have defaults, but just in case,
* ignore 'em
*/
if (tbinfo->attisdropped[adnum - 1])
continue;
attrdefs[j].dobj.objType = DO_ATTRDEF;
attrdefs[j].dobj.catId.tableoid = atooid(PQgetvalue(res, j, 0));
attrdefs[j].dobj.catId.oid = atooid(PQgetvalue(res, j, 1));
AssignDumpId(&attrdefs[j].dobj);
attrdefs[j].adtable = tbinfo;
attrdefs[j].adnum = adnum = atoi(PQgetvalue(res, j, 2));
attrdefs[j].adnum = adnum;
attrdefs[j].adef_expr = pg_strdup(PQgetvalue(res, j, 3));
attrdefs[j].dobj.name = pg_strdup(tbinfo->dobj.name);
@@ -6016,9 +6031,8 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
/*
* Defaults on a VIEW must always be dumped as separate ALTER
* TABLE commands. Defaults on regular tables are dumped as
* part of the CREATE TABLE if possible. To check if it's
* safe, we mark the default as needing to appear before the
* CREATE.
* part of the CREATE TABLE if possible, which it won't be
* if the column is not going to be emitted explicitly.
*/
if (tbinfo->relkind == RELKIND_VIEW)
{
@@ -6027,19 +6041,27 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
addObjectDependency(&attrdefs[j].dobj,
tbinfo->dobj.dumpId);
}
else if (!shouldPrintColumn(tbinfo, adnum - 1))
{
/* column will be suppressed, print default separately */
attrdefs[j].separate = true;
/* needed in case pre-7.3 DB: */
addObjectDependency(&attrdefs[j].dobj,
tbinfo->dobj.dumpId);
}
else
{
attrdefs[j].separate = false;
/*
* Mark the default as needing to appear before the table,
* so that any dependencies it has must be emitted before
* the CREATE TABLE. If this is not possible, we'll
* change to "separate" mode while sorting dependencies.
*/
addObjectDependency(&tbinfo->dobj,
attrdefs[j].dobj.dumpId);
}
if (adnum <= 0 || adnum > ntups)
{
write_msg(NULL, "invalid adnum value %d for table \"%s\"\n",
adnum, tbinfo->dobj.name);
exit_nicely();
}
tbinfo->attrdefs[adnum - 1] = &attrdefs[j];
}
PQclear(res);
@@ -6223,6 +6245,28 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
destroyPQExpBuffer(q);
}
/*
* Test whether a column should be printed as part of table's CREATE TABLE.
* Column number is zero-based.
*
* Normally this is always true, but it's false for dropped columns, as well
* as those that were inherited without any local definition. (If we print
* such a column it will mistakenly get pg_attribute.attislocal set to true.)
* However, in binary_upgrade mode, we must print all such columns anyway and
* fix the attislocal/attisdropped state later, so as to keep control of the
* physical column order.
*
* This function exists because there are scattered nonobvious places that
* must be kept in sync with this decision.
*/
bool
shouldPrintColumn(TableInfo *tbinfo, int colno)
{
if (binary_upgrade)
return true;
return (tbinfo->attislocal[colno] && !tbinfo->attisdropped[colno]);
}
/*
* getTSParsers:
@@ -12504,38 +12548,40 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
fmtId(tbinfo->dobj.name));
/*
* In case of a binary upgrade, we dump the table normally and attach
* it to the type afterward.
* Attach to type, if reloftype; except in case of a binary upgrade,
* we dump the table normally and attach it to the type afterward.
*/
if (tbinfo->reloftype && !binary_upgrade)
appendPQExpBuffer(q, " OF %s", tbinfo->reloftype);
/* Dump the attributes */
actual_atts = 0;
for (j = 0; j < tbinfo->numatts; j++)
{
/*
* Normally, dump if it's one of the table's own attrs, and not
* dropped. But for binary upgrade, dump all the columns.
* Normally, dump if it's locally defined in this table, and not
* dropped. But for binary upgrade, we'll dump all the columns,
* and then fix up the dropped and nonlocal cases below.
*/
if ((!tbinfo->inhAttrs[j] && !tbinfo->attisdropped[j]) ||
binary_upgrade)
if (shouldPrintColumn(tbinfo, j))
{
/*
* Default value --- suppress if inherited (except in
* binary-upgrade case, where we're not doing normal
* inheritance) or if it's to be printed separately.
* Default value --- suppress if to be printed separately.
*/
bool has_default = (tbinfo->attrdefs[j] != NULL
&& (!tbinfo->inhAttrDef[j] || binary_upgrade)
&& !tbinfo->attrdefs[j]->separate);
bool has_default = (tbinfo->attrdefs[j] != NULL &&
!tbinfo->attrdefs[j]->separate);
/*
* Not Null constraint --- suppress if inherited, except in
* binary-upgrade case.
* binary-upgrade case where that won't work.
*/
bool has_notnull = (tbinfo->notnull[j]
&& (!tbinfo->inhNotNull[j] || binary_upgrade));
bool has_notnull = (tbinfo->notnull[j] &&
(!tbinfo->inhNotNull[j] ||
binary_upgrade));
if (tbinfo->reloftype && !has_default && !has_notnull && !binary_upgrade)
/* Skip column if fully defined by reloftype */
if (tbinfo->reloftype &&
!has_default && !has_notnull && !binary_upgrade)
continue;
/* Format properly if not first attr */
@@ -12799,16 +12845,36 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
}
}
/* Loop dumping statistics and storage statements */
/*
* Dump additional per-column properties that we can't handle in the
* main CREATE TABLE command.
*/
for (j = 0; j < tbinfo->numatts; j++)
{
/* None of this applies to dropped columns */
if (tbinfo->attisdropped[j])
continue;
/*
* If we didn't dump the column definition explicitly above, and
* it is NOT NULL and did not inherit that property from a parent,
* we have to mark it separately.
*/
if (!shouldPrintColumn(tbinfo, j) &&
tbinfo->notnull[j] && !tbinfo->inhNotNull[j])
{
appendPQExpBuffer(q, "ALTER TABLE ONLY %s ",
fmtId(tbinfo->dobj.name));
appendPQExpBuffer(q, "ALTER COLUMN %s SET NOT NULL;\n",
fmtId(tbinfo->attnames[j]));
}
/*
* Dump per-column statistics information. We only issue an ALTER
* TABLE statement if the attstattarget entry for this column is
* non-negative (i.e. it's not the default value)
*/
if (tbinfo->attstattarget[j] >= 0 &&
!tbinfo->attisdropped[j])
if (tbinfo->attstattarget[j] >= 0)
{
appendPQExpBuffer(q, "ALTER TABLE ONLY %s ",
fmtId(tbinfo->dobj.name));
@@ -12822,7 +12888,7 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
* Dump per-column storage information. The statement is only
* dumped if the storage has been changed from the type's default.
*/
if (!tbinfo->attisdropped[j] && tbinfo->attstorage[j] != tbinfo->typstorage[j])
if (tbinfo->attstorage[j] != tbinfo->typstorage[j])
{
switch (tbinfo->attstorage[j])
{
@@ -12935,18 +13001,18 @@ dumpAttrDef(Archive *fout, AttrDefInfo *adinfo)
PQExpBuffer q;
PQExpBuffer delq;
/* Only print it if "separate" mode is selected */
if (!tbinfo->dobj.dump || !adinfo->separate || dataOnly)
/* Skip if table definition not to be dumped */
if (!tbinfo->dobj.dump || dataOnly)
return;
/* Don't print inherited defaults, either, except for binary upgrade */
if (tbinfo->inhAttrDef[adnum - 1] && !binary_upgrade)
/* Skip if not "separate"; it was dumped in the table's definition */
if (!adinfo->separate)
return;
q = createPQExpBuffer();
delq = createPQExpBuffer();
appendPQExpBuffer(q, "ALTER TABLE %s ",
appendPQExpBuffer(q, "ALTER TABLE ONLY %s ",
fmtId(tbinfo->dobj.name));
appendPQExpBuffer(q, "ALTER COLUMN %s SET DEFAULT %s;\n",
fmtId(tbinfo->attnames[adnum - 1]),