Code beautification for ATExecAttachPartition.

Amit Langote

Discussion: http://postgr.es/m/CAFjFpReT_kq_uwU_B8aWDxR7jNGE=P0iELycdq5oupi=xSQTOw@mail.gmail.com

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index b58c92d8466750d984008973599023e49c12d4e3..3c42e160b2dbe57f454b798c6bef99f798974fbe 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -13419,10 +13419,10 @@ ComputePartitionAttrs(Relation rel, List *partParams, AttrNumber *partattrs,
 static ObjectAddress
 ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
 {
-   Relation    attachRel,
+   Relation    attachrel,
                catalog;
-   List       *childrels;
-   TupleConstr *attachRel_constr;
+   List       *attachrel_children;
+   TupleConstr *attachrel_constr;
    List       *partConstraint,
               *existConstraint;
    SysScanDesc scan;
@@ -13434,22 +13434,22 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
    ObjectAddress address;
    const char *trigger_name;
 
-   attachRel = heap_openrv(cmd->name, AccessExclusiveLock);
+   attachrel = heap_openrv(cmd->name, AccessExclusiveLock);
 
    /*
     * Must be owner of both parent and source table -- parent was checked by
     * ATSimplePermissions call in ATPrepCmd
     */
-   ATSimplePermissions(attachRel, ATT_TABLE | ATT_FOREIGN_TABLE);
+   ATSimplePermissions(attachrel, ATT_TABLE | ATT_FOREIGN_TABLE);
 
    /* A partition can only have one parent */
-   if (attachRel->rd_rel->relispartition)
+   if (attachrel->rd_rel->relispartition)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("\"%s\" is already a partition",
-                       RelationGetRelationName(attachRel))));
+                       RelationGetRelationName(attachrel))));
 
-   if (OidIsValid(attachRel->rd_rel->reloftype))
+   if (OidIsValid(attachrel->rd_rel->reloftype))
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot attach a typed table as partition")));
@@ -13462,7 +13462,7 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
    ScanKeyInit(&skey,
                Anum_pg_inherits_inhrelid,
                BTEqualStrategyNumber, F_OIDEQ,
-               ObjectIdGetDatum(RelationGetRelid(attachRel)));
+               ObjectIdGetDatum(RelationGetRelid(attachrel)));
    scan = systable_beginscan(catalog, InheritsRelidSeqnoIndexId, true,
                              NULL, 1, &skey);
    if (HeapTupleIsValid(systable_getnext(scan)))
@@ -13475,11 +13475,11 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
    ScanKeyInit(&skey,
                Anum_pg_inherits_inhparent,
                BTEqualStrategyNumber, F_OIDEQ,
-               ObjectIdGetDatum(RelationGetRelid(attachRel)));
+               ObjectIdGetDatum(RelationGetRelid(attachrel)));
    scan = systable_beginscan(catalog, InheritsParentIndexId, true, NULL,
                              1, &skey);
    if (HeapTupleIsValid(systable_getnext(scan)) &&
-       attachRel->rd_rel->relkind == RELKIND_RELATION)
+       attachrel->rd_rel->relkind == RELKIND_RELATION)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot attach inheritance parent as partition")));
@@ -13487,22 +13487,22 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
    heap_close(catalog, AccessShareLock);
 
    /*
-    * Prevent circularity by seeing if rel is a partition of attachRel. (In
+    * Prevent circularity by seeing if rel is a partition of attachrel. (In
     * particular, this disallows making a rel a partition of itself.)
     */
-   childrels = find_all_inheritors(RelationGetRelid(attachRel),
-                                   AccessShareLock, NULL);
-   if (list_member_oid(childrels, RelationGetRelid(rel)))
+   attachrel_children = find_all_inheritors(RelationGetRelid(attachrel),
+                                            AccessShareLock, NULL);
+   if (list_member_oid(attachrel_children, RelationGetRelid(rel)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_TABLE),
                 errmsg("circular inheritance not allowed"),
                 errdetail("\"%s\" is already a child of \"%s\".",
                           RelationGetRelationName(rel),
-                          RelationGetRelationName(attachRel))));
+                          RelationGetRelationName(attachrel))));
 
    /* Temp parent cannot have a partition that is itself not a temp */
    if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
-       attachRel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
+       attachrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot attach a permanent relation as partition of temporary relation \"%s\"",
@@ -13516,30 +13516,30 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
                 errmsg("cannot attach as partition of temporary relation of another session")));
 
    /* Ditto for the partition */
-   if (attachRel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
-       !attachRel->rd_islocaltemp)
+   if (attachrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
+       !attachrel->rd_islocaltemp)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot attach temporary relation of another session as partition")));
 
    /* If parent has OIDs then child must have OIDs */
-   if (rel->rd_rel->relhasoids && !attachRel->rd_rel->relhasoids)
+   if (rel->rd_rel->relhasoids && !attachrel->rd_rel->relhasoids)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot attach table \"%s\" without OIDs as partition of"
-                       " table \"%s\" with OIDs", RelationGetRelationName(attachRel),
+                       " table \"%s\" with OIDs", RelationGetRelationName(attachrel),
                        RelationGetRelationName(rel))));
 
-   /* OTOH, if parent doesn't have them, do not allow in attachRel either */
-   if (attachRel->rd_rel->relhasoids && !rel->rd_rel->relhasoids)
+   /* OTOH, if parent doesn't have them, do not allow in attachrel either */
+   if (attachrel->rd_rel->relhasoids && !rel->rd_rel->relhasoids)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("cannot attach table \"%s\" with OIDs as partition of table"
-                       " \"%s\" without OIDs", RelationGetRelationName(attachRel),
+                       " \"%s\" without OIDs", RelationGetRelationName(attachrel),
                        RelationGetRelationName(rel))));
 
-   /* Check if there are any columns in attachRel that aren't in the parent */
-   tupleDesc = RelationGetDescr(attachRel);
+   /* Check if there are any columns in attachrel that aren't in the parent */
+   tupleDesc = RelationGetDescr(attachrel);
    natts = tupleDesc->natts;
    for (attno = 1; attno <= natts; attno++)
    {
@@ -13557,7 +13557,7 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
            ereport(ERROR,
                    (errcode(ERRCODE_DATATYPE_MISMATCH),
                     errmsg("table \"%s\" contains column \"%s\" not found in parent \"%s\"",
-                           RelationGetRelationName(attachRel), attributeName,
+                           RelationGetRelationName(attachrel), attributeName,
                            RelationGetRelationName(rel)),
                     errdetail("New partition should contain only the columns present in parent.")));
    }
@@ -13567,34 +13567,34 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
     * currently don't allow it to become a partition.  See also prohibitions
     * in ATExecAddInherit() and CreateTrigger().
     */
-   trigger_name = FindTriggerIncompatibleWithInheritance(attachRel->trigdesc);
+   trigger_name = FindTriggerIncompatibleWithInheritance(attachrel->trigdesc);
    if (trigger_name != NULL)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("trigger \"%s\" prevents table \"%s\" from becoming a partition",
-                       trigger_name, RelationGetRelationName(attachRel)),
+                       trigger_name, RelationGetRelationName(attachrel)),
                 errdetail("ROW triggers with transition tables are not supported on partitions")));
 
    /* OK to create inheritance.  Rest of the checks performed there */
-   CreateInheritance(attachRel, rel);
+   CreateInheritance(attachrel, rel);
 
    /*
     * Check that the new partition's bound is valid and does not overlap any
     * of existing partitions of the parent - note that it does not return on
     * error.
     */
-   check_new_partition_bound(RelationGetRelationName(attachRel), rel,
+   check_new_partition_bound(RelationGetRelationName(attachrel), rel,
                              cmd->bound);
 
    /* Update the pg_class entry. */
-   StorePartitionBound(attachRel, rel, cmd->bound);
+   StorePartitionBound(attachrel, rel, cmd->bound);
 
    /*
     * Generate partition constraint from the partition bound specification.
     * If the parent itself is a partition, make sure to include its
     * constraint as well.
     */
-   partConstraint = list_concat(get_qual_from_partbound(attachRel, rel,
+   partConstraint = list_concat(get_qual_from_partbound(attachrel, rel,
                                                         cmd->bound),
                                 RelationGetPartitionQual(rel));
    partConstraint = (List *) eval_const_expressions(NULL,
@@ -13612,20 +13612,20 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
     * There is a case in which we cannot rely on just the result of the
     * proof.
     */
-   attachRel_constr = tupleDesc->constr;
+   attachrel_constr = tupleDesc->constr;
    existConstraint = NIL;
-   if (attachRel_constr != NULL)
+   if (attachrel_constr != NULL)
    {
-       int         num_check = attachRel_constr->num_check;
+       int         num_check = attachrel_constr->num_check;
        int         i;
 
-       if (attachRel_constr->has_not_null)
+       if (attachrel_constr->has_not_null)
        {
-           int         natts = attachRel->rd_att->natts;
+           int         natts = attachrel->rd_att->natts;
 
            for (i = 1; i <= natts; i++)
            {
-               Form_pg_attribute att = attachRel->rd_att->attrs[i - 1];
+               Form_pg_attribute att = attachrel->rd_att->attrs[i - 1];
 
                if (att->attnotnull && !att->attisdropped)
                {
@@ -13659,10 +13659,10 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
             * If this constraint hasn't been fully validated yet, we must
             * ignore it here.
             */
-           if (!attachRel_constr->check[i].ccvalid)
+           if (!attachrel_constr->check[i].ccvalid)
                continue;
 
-           cexpr = stringToNode(attachRel_constr->check[i].ccbin);
+           cexpr = stringToNode(attachrel_constr->check[i].ccbin);
 
            /*
             * Run each expression through const-simplification and
@@ -13684,28 +13684,25 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
            skip_validate = true;
    }
 
-   /* It's safe to skip the validation scan after all */
    if (skip_validate)
+   {
+       /* No need to scan the table after all. */
        ereport(INFO,
                (errmsg("partition constraint for table \"%s\" is implied by existing constraints",
-                       RelationGetRelationName(attachRel))));
-
-   /*
-    * Set up to have the table be scanned to validate the partition
-    * constraint (see partConstraint above).  If it's a partitioned table, we
-    * instead schedule its leaf partitions to be scanned.
-    */
-   if (!skip_validate)
+                       RelationGetRelationName(attachrel))));
+   }
+   else
    {
+       /* Constraints proved insufficient, so we need to scan the table. */
        List       *all_parts;
        ListCell   *lc;
 
        /* Take an exclusive lock on the partitions to be checked */
-       if (attachRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
-           all_parts = find_all_inheritors(RelationGetRelid(attachRel),
+       if (attachrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+           all_parts = find_all_inheritors(RelationGetRelid(attachrel),
                                            AccessExclusiveLock, NULL);
        else
-           all_parts = list_make1_oid(RelationGetRelid(attachRel));
+           all_parts = list_make1_oid(RelationGetRelid(attachrel));
 
        foreach(lc, all_parts)
        {
@@ -13716,23 +13713,23 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
            bool        found_whole_row;
 
            /* Lock already taken */
-           if (part_relid != RelationGetRelid(attachRel))
+           if (part_relid != RelationGetRelid(attachrel))
                part_rel = heap_open(part_relid, NoLock);
            else
-               part_rel = attachRel;
+               part_rel = attachrel;
 
            /*
-            * Skip if it's a partitioned table.  Only RELKIND_RELATION
-            * relations (ie, leaf partitions) need to be scanned.
+            * Skip if the partition is itself a partitioned table.  We can
+            * only ever scan RELKIND_RELATION relations.
             */
-           if (part_rel != attachRel &&
-               part_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+           if (part_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
            {
-               heap_close(part_rel, NoLock);
+               if (part_rel != attachrel)
+                   heap_close(part_rel, NoLock);
                continue;
            }
 
-           /* Grab a work queue entry */
+           /* Grab a work queue entry. */
            tab = ATGetQueueEntry(wqueue, part_rel);
 
            /* Adjust constraint to match this partition */
@@ -13746,15 +13743,15 @@ ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
                elog(ERROR, "unexpected whole-row reference found in partition key");
 
            /* keep our lock until commit */
-           if (part_rel != attachRel)
+           if (part_rel != attachrel)
                heap_close(part_rel, NoLock);
        }
    }
 
-   ObjectAddressSet(address, RelationRelationId, RelationGetRelid(attachRel));
+   ObjectAddressSet(address, RelationRelationId, RelationGetRelid(attachrel));
 
    /* keep our lock until commit */
-   heap_close(attachRel, NoLock);
+   heap_close(attachrel, NoLock);
 
    return address;
 }