Clean up comments

Reformat some of the comments in MergeAttributes().  A lot of code has
been added here over time, and the comments could use a bit of editing
to make the code flow read better.

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 3a93c41d6ab1c6f6140015da137cadba15efe296..3e2c5f797cd7187c4abc02dcc0f1cc30e69c863f 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -2562,13 +2562,16 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                Oid                     defCollId;
 
                                /*
-                                * Yes, try to merge the two column definitions. They must
-                                * have the same type, typmod, and collation.
+                                * Yes, try to merge the two column definitions.
                                 */
                                ereport(NOTICE,
                                                (errmsg("merging multiple inherited definitions of column \"%s\"",
                                                                attributeName)));
                                def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
+
+                               /*
+                                * Must have the same type and typmod
+                                */
                                typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
                                if (defTypeId != attribute->atttypid ||
                                        deftypmod != attribute->atttypmod)
@@ -2581,6 +2584,10 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                                                                                deftypmod),
                                                                           format_type_with_typemod(attribute->atttypid,
                                                                                                                                attribute->atttypmod))));
+
+                               /*
+                                * Must have the same collation
+                                */
                                defCollId = GetColumnDefCollation(NULL, def, defTypeId);
                                if (defCollId != attribute->attcollation)
                                        ereport(ERROR,
@@ -2591,7 +2598,9 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                           get_collation_name(defCollId),
                                                                           get_collation_name(attribute->attcollation))));
 
-                               /* Copy/check storage parameter */
+                               /*
+                                * Copy/check storage parameter
+                                */
                                if (def->storage == 0)
                                        def->storage = attribute->attstorage;
                                else if (def->storage != attribute->attstorage)
@@ -2603,7 +2612,9 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                           storage_name(def->storage),
                                                                           storage_name(attribute->attstorage))));
 
-                               /* Copy/check compression parameter */
+                               /*
+                                * Copy/check compression parameter
+                                */
                                if (CompressionMethodIsValid(attribute->attcompression))
                                {
                                        const char *compression =
@@ -2619,18 +2630,27 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                 errdetail("%s versus %s", def->compression, compression)));
                                }
 
-                               def->inhcount++;
-                               /* Merge of NOT NULL constraints = OR 'em together */
+                               /*
+                                * Merge of NOT NULL constraints = OR 'em together
+                                */
                                def->is_not_null |= attribute->attnotnull;
-                               /* Default and other constraints are handled below */
-                               newattmap->attnums[parent_attno - 1] = exist_attno;
 
-                               /* Check for GENERATED conflicts */
+                               /*
+                                * Check for GENERATED conflicts
+                                */
                                if (def->generated != attribute->attgenerated)
                                        ereport(ERROR,
                                                        (errcode(ERRCODE_DATATYPE_MISMATCH),
                                                         errmsg("inherited column \"%s\" has a generation conflict",
                                                                        attributeName)));
+
+                               /*
+                                * Default and other constraints are handled below
+                                */
+
+                               def->inhcount++;
+
+                               newattmap->attnums[parent_attno - 1] = exist_attno;
                        }
                        else
                        {
@@ -2853,8 +2873,7 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                Assert(!is_partition);
 
                                /*
-                                * Yes, try to merge the two column definitions. They must
-                                * have the same type, typmod, and collation.
+                                * Yes, try to merge the two column definitions.
                                 */
                                if (exist_attno == schema_attno)
                                        ereport(NOTICE,
@@ -2865,6 +2884,10 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                        (errmsg("moving and merging column \"%s\" with inherited definition", attributeName),
                                                         errdetail("User-specified column moved to the position of the inherited column.")));
                                def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
+
+                               /*
+                                * Must have the same type and typmod
+                                */
                                typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
                                typenameTypeIdAndMod(NULL, newdef->typeName, &newTypeId, &newtypmod);
                                if (defTypeId != newTypeId || deftypmod != newtypmod)
@@ -2877,6 +2900,10 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                                                                                deftypmod),
                                                                           format_type_with_typemod(newTypeId,
                                                                                                                                newtypmod))));
+
+                               /*
+                                * Must have the same collation
+                                */
                                defcollid = GetColumnDefCollation(NULL, def, defTypeId);
                                newcollid = GetColumnDefCollation(NULL, newdef, newTypeId);
                                if (defcollid != newcollid)
@@ -2894,7 +2921,9 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                 */
                                def->identity = newdef->identity;
 
-                               /* Copy storage parameter */
+                               /*
+                                * Copy storage parameter
+                                */
                                if (def->storage == 0)
                                        def->storage = newdef->storage;
                                else if (newdef->storage != 0 && def->storage != newdef->storage)
@@ -2906,7 +2935,9 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                           storage_name(def->storage),
                                                                           storage_name(newdef->storage))));
 
-                               /* Copy compression parameter */
+                               /*
+                                * Copy compression parameter
+                                */
                                if (def->compression == NULL)
                                        def->compression = newdef->compression;
                                else if (newdef->compression != NULL)
@@ -2919,9 +2950,9 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                 errdetail("%s versus %s", def->compression, newdef->compression)));
                                }
 
-                               /* Mark the column as locally defined */
-                               def->is_local = true;
-                               /* Merge of NOT NULL constraints = OR 'em together */
+                               /*
+                                * Merge of NOT NULL constraints = OR 'em together
+                                */
                                def->is_not_null |= newdef->is_not_null;
 
                                /*
@@ -2962,12 +2993,17 @@ MergeAttributes(List *schema, List *supers, char relpersistence,
                                                                 errhint("A child table column cannot be generated unless its parent column is.")));
                                }
 
-                               /* If new def has a default, override previous default */
+                               /*
+                                * If new def has a default, override previous default
+                                */
                                if (newdef->raw_default != NULL)
                                {
                                        def->raw_default = newdef->raw_default;
                                        def->cooked_default = newdef->cooked_default;
                                }
+
+                               /* Mark the column as locally defined */
+                               def->is_local = true;
                        }
                        else
                        {