Code review for patch to dump primary and unique constraints as

constraints, rather than as CREATE INDEX commands.

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 22dfa23a965e73e1f4df3da5591afaddcae54758..f12be8cbfd45740f4adfe6f371e5b5bd449144f7 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -22,7 +22,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/bin/pg_dump/pg_dump.c,v 1.282 2002/08/15 16:36:06 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/bin/pg_dump/pg_dump.c,v 1.283 2002/08/16 21:03:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -5286,7 +5286,7 @@ dumpOneTable(Archive *fout, TableInfo *tbinfo, TableInfo *g_tblinfo)
                        if (tbinfo->attstattarget[j] >= 0 &&
                                !tbinfo->attisdropped[j])
                        {
-                               appendPQExpBuffer(q, "ALTER TABLE %s ",
+                               appendPQExpBuffer(q, "ALTER TABLE ONLY %s ",
                                                                  fmtId(tbinfo->relname, force_quotes));
                                appendPQExpBuffer(q, "ALTER COLUMN %s ",
                                                                  fmtId(tbinfo->attnames[j], force_quotes));
@@ -5388,6 +5388,13 @@ dumpIndexes(Archive *fout, TableInfo *tblinfo, int numTables)
                /* Make sure we are in proper schema so indexdef is right */
                selectSourceSchema(tbinfo->relnamespace->nspname);
 
+               /*
+                * The point of the messy-looking outer join is to find a constraint
+                * that is related by an internal dependency link to the index.
+                * If we find one, we emit an ADD CONSTRAINT command instead of
+                * a CREATE INDEX command.  We assume an index won't have more than
+                * one internal dependency.
+                */
                resetPQExpBuffer(query);
                if (g_fout->remoteVersion >= 70300)
                        appendPQExpBuffer(query,
@@ -5399,8 +5406,13 @@ dumpIndexes(Archive *fout, TableInfo *tblinfo, int numTables)
                                                          "coalesce(c.contype, '0') as contype " 
                                                          "FROM pg_catalog.pg_index i "
                                                          "JOIN pg_catalog.pg_class t ON (t.oid = i.indexrelid) "
-                                                         "LEFT OUTER JOIN pg_catalog.pg_constraint c "
-                                                         "  ON (c.conrelid = i.indrelid AND c.conname = t.relname) "
+                                                         "LEFT JOIN pg_catalog.pg_depend d "
+                                                         "ON (d.classid = t.tableoid "
+                                                         "AND d.objid = t.oid "
+                                                         "AND d.deptype = 'i') "
+                                                         "LEFT JOIN pg_catalog.pg_constraint c "
+                                                         "ON (d.refclassid = c.tableoid "
+                                                         "AND d.refobjid = c.oid) "
                                                          "WHERE i.indrelid = '%s'::pg_catalog.oid "
                                                          "ORDER BY indexrelname",
                                                          tbinfo->oid);
@@ -5411,8 +5423,7 @@ dumpIndexes(Archive *fout, TableInfo *tblinfo, int numTables)
                                                          "pg_get_indexdef(i.indexrelid) as indexdef, "
                                                          "i.indkey, "
                                                          "t.relnatts as indnkeys, "
-                                                         "CASE WHEN i.indisprimary IS TRUE THEN "
-                                                         "  'p'::char "
+                                                         "CASE WHEN i.indisprimary THEN 'p'::char "
                                                          "ELSE '0'::char END as contype "
                                                          "FROM pg_index i, pg_class t "
                                                          "WHERE t.oid = i.indexrelid "
@@ -5442,17 +5453,19 @@ dumpIndexes(Archive *fout, TableInfo *tblinfo, int numTables)
                        const char *indexreloid = PQgetvalue(res, j, i_indexreloid);
                        const char *indexrelname = PQgetvalue(res, j, i_indexrelname);
                        const char *indexdef = PQgetvalue(res, j, i_indexdef);
-                       const char *contype = PQgetvalue(res, j, i_contype);
+                       char contype = *(PQgetvalue(res, j, i_contype));
 
                        resetPQExpBuffer(q);
                        resetPQExpBuffer(delq);
 
-                       if (strcmp(contype, "p") == 0 || strcmp(contype, "u") == 0)
+                       if (contype == 'p' || contype == 'u')
                        {
                                /*
-                                * Constraints which are marked as so (created with a
-                                * constraint creation utility statement, not an index
-                                * creation statment) should be regenerated as such.
+                                * If we found a constraint matching the index, emit
+                                * ADD CONSTRAINT not CREATE INDEX.
+                                *
+                                * In a pre-7.3 database, we take this path iff the index
+                                * was marked indisprimary.
                                 */
                                int indnkeys = atoi(PQgetvalue(res, j, i_indnkeys));
                                char **indkeys = (char **) malloc(indnkeys * sizeof(char *));
@@ -5461,11 +5474,11 @@ dumpIndexes(Archive *fout, TableInfo *tblinfo, int numTables)
                                parseNumericArray(PQgetvalue(res, j, i_indkey),
                                                                  indkeys, indnkeys);
 
-                               appendPQExpBuffer(q, "ALTER TABLE %s ADD ",
+                               appendPQExpBuffer(q, "ALTER TABLE ONLY %s ",
                                                                  fmtId(tbinfo->relname, force_quotes));
-                               appendPQExpBuffer(q, "CONSTRAINT %s %s (",
+                               appendPQExpBuffer(q, "ADD CONSTRAINT %s %s (",
                                                                  fmtId(indexrelname, force_quotes),
-                                                                 strcmp(contype, "p") == 0 ? "PRIMARY KEY" : "UNIQUE");
+                                                                 contype == 'p' ? "PRIMARY KEY" : "UNIQUE");
 
                                for (k = 0; k < indnkeys; k++)
                                {
@@ -5483,12 +5496,20 @@ dumpIndexes(Archive *fout, TableInfo *tblinfo, int numTables)
 
                                appendPQExpBuffer(q, ");\n");
 
+                               /* DROP must be fully qualified in case same name appears in pg_catalog */
+                               appendPQExpBuffer(delq, "ALTER TABLE ONLY %s.",
+                                                                 fmtId(tbinfo->relnamespace->nspname, force_quotes));
+                               appendPQExpBuffer(delq, "%s ",
+                                                                 fmtId(tbinfo->relname, force_quotes));
+                               appendPQExpBuffer(delq, "DROP CONSTRAINT %s;\n",
+                                                                 fmtId(indexrelname, force_quotes));
+
                                ArchiveEntry(fout, indexreloid,
                                                         indexrelname,
                                                         tbinfo->relnamespace->nspname,
                                                         tbinfo->usename,
                                                         "CONSTRAINT", NULL,
-                                                        q->data, "",
+                                                        q->data, delq->data,
                                                         NULL, NULL, NULL);
 
                                for (k = 0; k < indnkeys; k++)