Improve performance of binary_upgrade_set_pg_class_oids().

This function generates the commands that preserve the OIDs and
relfilenodes of relations during pg_upgrade.  It is called once per
relevant relation, and each such call executes a relatively
expensive query to retrieve information for a single pg_class_oid.
This can cause pg_dump to take significantly longer when
--binary-upgrade is specified, especially when there are many
tables.

This commit improves the performance of this function by gathering
all the required pg_class information with a single query at the
beginning of pg_dump.  This information is stored in a sorted array
that binary_upgrade_set_pg_class_oids() can bsearch() for what it
needs.  This follows a similar approach as commit d5e8930f50, which
introduced a sorted array for role information.

With this patch, 'pg_dump --binary-upgrade' will use more memory,
but that isn't expected to be too egregious.  Per the mailing list
discussion, folks feel that this is worth the trade-off.

Reviewed-by: Corey Huinker, Michael Paquier, Daniel Gustafsson
Discussion: https://postgr.es/m/20240418041712.GA3441570%40nathanxps13

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 6920b42bd2666d6f49d8a59c2c218cc772b2f457..5426f1177c49c3554a841834f1afda4f6ccee0a5 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -55,6 +55,7 @@
 #include "catalog/pg_trigger_d.h"
 #include "catalog/pg_type_d.h"
 #include "common/connect.h"
+#include "common/int.h"
 #include "common/relpath.h"
 #include "compress_io.h"
 #include "dumputils.h"
@@ -92,6 +93,17 @@ typedef struct
    int         objsubid;       /* subobject (table column #) */
 } SecLabelItem;
 
+typedef struct
+{
+   Oid         oid;            /* object OID */
+   char        relkind;        /* object kind */
+   RelFileNumber relfilenumber;    /* object filenode */
+   Oid         toast_oid;      /* toast table OID */
+   RelFileNumber toast_relfilenumber;  /* toast table filenode */
+   Oid         toast_index_oid;    /* toast table index OID */
+   RelFileNumber toast_index_relfilenumber;    /* toast table index filenode */
+} BinaryUpgradeClassOidItem;
+
 typedef enum OidOptions
 {
    zeroIsError = 1,
@@ -157,6 +169,10 @@ static int ncomments = 0;
 static SecLabelItem *seclabels = NULL;
 static int nseclabels = 0;
 
+/* sorted table of pg_class information for binary upgrade */
+static BinaryUpgradeClassOidItem *binaryUpgradeClassOids = NULL;
+static int nbinaryUpgradeClassOids = 0;
+
 /*
  * The default number of rows per INSERT when
  * --inserts is specified without --rows-per-insert
@@ -322,6 +338,7 @@ static void binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
 static void binary_upgrade_set_type_oids_by_rel(Archive *fout,
                                                PQExpBuffer upgrade_buffer,
                                                const TableInfo *tbinfo);
+static void collectBinaryUpgradeClassOids(Archive *fout);
 static void binary_upgrade_set_pg_class_oids(Archive *fout,
                                             PQExpBuffer upgrade_buffer,
                                             Oid pg_class_oid);
@@ -971,6 +988,10 @@ main(int argc, char **argv)
    if (!dopt.no_security_labels)
        collectSecLabels(fout);
 
+   /* For binary upgrade mode, collect required pg_class information. */
+   if (dopt.binary_upgrade)
+       collectBinaryUpgradeClassOids(fout);
+
    /* Lastly, create dummy objects to represent the section boundaries */
    boundaryObjs = createBoundaryObjects();
 
@@ -5383,18 +5404,67 @@ binary_upgrade_set_type_oids_by_rel(Archive *fout,
                                                 pg_type_oid, false, false);
 }
 
+/*
+ * bsearch() comparator for BinaryUpgradeClassOidItem
+ */
+static int
+BinaryUpgradeClassOidItemCmp(const void *p1, const void *p2)
+{
+   BinaryUpgradeClassOidItem v1 = *((const BinaryUpgradeClassOidItem *) p1);
+   BinaryUpgradeClassOidItem v2 = *((const BinaryUpgradeClassOidItem *) p2);
+
+   return pg_cmp_u32(v1.oid, v2.oid);
+}
+
+/*
+ * collectBinaryUpgradeClassOids
+ *
+ * Construct a table of pg_class information required for
+ * binary_upgrade_set_pg_class_oids().  The table is sorted by OID for speed in
+ * lookup.
+ */
+static void
+collectBinaryUpgradeClassOids(Archive *fout)
+{
+   PGresult   *res;
+   const char *query;
+
+   query = "SELECT c.oid, c.relkind, c.relfilenode, c.reltoastrelid, "
+       "ct.relfilenode, i.indexrelid, cti.relfilenode "
+       "FROM pg_catalog.pg_class c LEFT JOIN pg_catalog.pg_index i "
+       "ON (c.reltoastrelid = i.indrelid AND i.indisvalid) "
+       "LEFT JOIN pg_catalog.pg_class ct ON (c.reltoastrelid = ct.oid) "
+       "LEFT JOIN pg_catalog.pg_class AS cti ON (i.indexrelid = cti.oid) "
+       "ORDER BY c.oid;";
+
+   res = ExecuteSqlQuery(fout, query, PGRES_TUPLES_OK);
+
+   nbinaryUpgradeClassOids = PQntuples(res);
+   binaryUpgradeClassOids = (BinaryUpgradeClassOidItem *)
+       pg_malloc(nbinaryUpgradeClassOids * sizeof(BinaryUpgradeClassOidItem));
+
+   for (int i = 0; i < nbinaryUpgradeClassOids; i++)
+   {
+       binaryUpgradeClassOids[i].oid = atooid(PQgetvalue(res, i, 0));
+       binaryUpgradeClassOids[i].relkind = *PQgetvalue(res, i, 1);
+       binaryUpgradeClassOids[i].relfilenumber = atooid(PQgetvalue(res, i, 2));
+       binaryUpgradeClassOids[i].toast_oid = atooid(PQgetvalue(res, i, 3));
+       binaryUpgradeClassOids[i].toast_relfilenumber = atooid(PQgetvalue(res, i, 4));
+       binaryUpgradeClassOids[i].toast_index_oid = atooid(PQgetvalue(res, i, 5));
+       binaryUpgradeClassOids[i].toast_index_relfilenumber = atooid(PQgetvalue(res, i, 6));
+   }
+
+   PQclear(res);
+}
+
 static void
 binary_upgrade_set_pg_class_oids(Archive *fout,
                                 PQExpBuffer upgrade_buffer, Oid pg_class_oid)
 {
-   PQExpBuffer upgrade_query = createPQExpBuffer();
-   PGresult   *upgrade_res;
-   RelFileNumber relfilenumber;
-   Oid         toast_oid;
-   RelFileNumber toast_relfilenumber;
-   char        relkind;
-   Oid         toast_index_oid;
-   RelFileNumber toast_index_relfilenumber;
+   BinaryUpgradeClassOidItem key = {0};
+   BinaryUpgradeClassOidItem *entry;
+
+   Assert(binaryUpgradeClassOids);
 
    /*
     * Preserve the OID and relfilenumber of the table, table's index, table's
@@ -5407,35 +5477,16 @@ binary_upgrade_set_pg_class_oids(Archive *fout,
     * by the new backend, so we can copy the files during binary upgrade
     * without worrying about this case.
     */
-   appendPQExpBuffer(upgrade_query,
-                     "SELECT c.relkind, c.relfilenode, c.reltoastrelid, ct.relfilenode AS toast_relfilenode, i.indexrelid, cti.relfilenode AS toast_index_relfilenode "
-                     "FROM pg_catalog.pg_class c LEFT JOIN "
-                     "pg_catalog.pg_index i ON (c.reltoastrelid = i.indrelid AND i.indisvalid) "
-                     "LEFT JOIN pg_catalog.pg_class ct ON (c.reltoastrelid = ct.oid) "
-                     "LEFT JOIN pg_catalog.pg_class AS cti ON (i.indexrelid = cti.oid) "
-                     "WHERE c.oid = '%u'::pg_catalog.oid;",
-                     pg_class_oid);
-
-   upgrade_res = ExecuteSqlQueryForSingleRow(fout, upgrade_query->data);
-
-   relkind = *PQgetvalue(upgrade_res, 0, PQfnumber(upgrade_res, "relkind"));
-
-   relfilenumber = atooid(PQgetvalue(upgrade_res, 0,
-                                     PQfnumber(upgrade_res, "relfilenode")));
-   toast_oid = atooid(PQgetvalue(upgrade_res, 0,
-                                 PQfnumber(upgrade_res, "reltoastrelid")));
-   toast_relfilenumber = atooid(PQgetvalue(upgrade_res, 0,
-                                           PQfnumber(upgrade_res, "toast_relfilenode")));
-   toast_index_oid = atooid(PQgetvalue(upgrade_res, 0,
-                                       PQfnumber(upgrade_res, "indexrelid")));
-   toast_index_relfilenumber = atooid(PQgetvalue(upgrade_res, 0,
-                                                 PQfnumber(upgrade_res, "toast_index_relfilenode")));
+   key.oid = pg_class_oid;
+   entry = bsearch(&key, binaryUpgradeClassOids, nbinaryUpgradeClassOids,
+                   sizeof(BinaryUpgradeClassOidItem),
+                   BinaryUpgradeClassOidItemCmp);
 
    appendPQExpBufferStr(upgrade_buffer,
                         "\n-- For binary upgrade, must preserve pg_class oids and relfilenodes\n");
 
-   if (relkind != RELKIND_INDEX &&
-       relkind != RELKIND_PARTITIONED_INDEX)
+   if (entry->relkind != RELKIND_INDEX &&
+       entry->relkind != RELKIND_PARTITIONED_INDEX)
    {
        appendPQExpBuffer(upgrade_buffer,
                          "SELECT pg_catalog.binary_upgrade_set_next_heap_pg_class_oid('%u'::pg_catalog.oid);\n",
@@ -5446,32 +5497,33 @@ binary_upgrade_set_pg_class_oids(Archive *fout,
         * partitioned tables have a relfilenumber, which should not be
         * preserved when upgrading.
         */
-       if (RelFileNumberIsValid(relfilenumber) && relkind != RELKIND_PARTITIONED_TABLE)
+       if (RelFileNumberIsValid(entry->relfilenumber) &&
+           entry->relkind != RELKIND_PARTITIONED_TABLE)
            appendPQExpBuffer(upgrade_buffer,
                              "SELECT pg_catalog.binary_upgrade_set_next_heap_relfilenode('%u'::pg_catalog.oid);\n",
-                             relfilenumber);
+                             entry->relfilenumber);
 
        /*
         * In a pre-v12 database, partitioned tables might be marked as having
         * toast tables, but we should ignore them if so.
         */
-       if (OidIsValid(toast_oid) &&
-           relkind != RELKIND_PARTITIONED_TABLE)
+       if (OidIsValid(entry->toast_oid) &&
+           entry->relkind != RELKIND_PARTITIONED_TABLE)
        {
            appendPQExpBuffer(upgrade_buffer,
                              "SELECT pg_catalog.binary_upgrade_set_next_toast_pg_class_oid('%u'::pg_catalog.oid);\n",
-                             toast_oid);
+                             entry->toast_oid);
            appendPQExpBuffer(upgrade_buffer,
                              "SELECT pg_catalog.binary_upgrade_set_next_toast_relfilenode('%u'::pg_catalog.oid);\n",
-                             toast_relfilenumber);
+                             entry->toast_relfilenumber);
 
            /* every toast table has an index */
            appendPQExpBuffer(upgrade_buffer,
                              "SELECT pg_catalog.binary_upgrade_set_next_index_pg_class_oid('%u'::pg_catalog.oid);\n",
-                             toast_index_oid);
+                             entry->toast_index_oid);
            appendPQExpBuffer(upgrade_buffer,
                              "SELECT pg_catalog.binary_upgrade_set_next_index_relfilenode('%u'::pg_catalog.oid);\n",
-                             toast_index_relfilenumber);
+                             entry->toast_index_relfilenumber);
        }
    }
    else
@@ -5482,14 +5534,10 @@ binary_upgrade_set_pg_class_oids(Archive *fout,
                          pg_class_oid);
        appendPQExpBuffer(upgrade_buffer,
                          "SELECT pg_catalog.binary_upgrade_set_next_index_relfilenode('%u'::pg_catalog.oid);\n",
-                         relfilenumber);
+                         entry->relfilenumber);
    }
 
-   PQclear(upgrade_res);
-
    appendPQExpBufferChar(upgrade_buffer, '\n');
-
-   destroyPQExpBuffer(upgrade_query);
 }
 
 /*

diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e6c1caf64983f4d93e2cb3921fa16b616a9586e8..e710fa48e596fbed874621610301afe303bded5f 100644 (file)
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -253,6 +253,7 @@ BernoulliSamplerData
 BgWorkerStartTime
 BgwHandleStatus
 BinaryArithmFunc
+BinaryUpgradeClassOidItem
 BindParamCbData
 BipartiteMatchState
 BitString