On 06.12.23 09:23, Peter Eisentraut wrote:
The (now) second patch is also still of interest to me, but I have since
noticed that I think [0] should be fixed first, but to make that fix
simpler, I would like the first patch from here.
[0]:
https://www.postgresql.org/message-id/flat/24656cec-d6ef-4d15-8b5b-e8dfc9c833a7%40eisentraut.org
The remaining patch in this series needed a rebase and adjustment.
The above precondition still applies.
From c4c4462fa58c73fc383c4935c8d2753b7a0b4c9d Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Mon, 22 Jan 2024 13:23:43 +0100
Subject: [PATCH v5] MergeAttributes: convert pg_attribute back to ColumnDef
before comparing
MergeAttributes() has a loop to merge multiple inheritance parents
into a column column definition. The merged-so-far definition is
stored in a ColumnDef node. If we have to merge columns from multiple
inheritance parents (if the name matches), then we have to check
whether various column properties (type, collation, etc.) match. The
current code extracts the pg_attribute value of the
currently-considered inheritance parent and compares it against the
merged-so-far ColumnDef value. If the currently considered column
doesn't match any previously inherited column, we make a new ColumnDef
node from the pg_attribute information and add it to the column list.
This patch rearranges this so that we create the ColumnDef node first
in either case. Then the code that checks the column properties for
compatibility compares ColumnDef against ColumnDef (instead of
ColumnDef against pg_attribute). This makes the code more symmetric
and easier to follow. Also, later in MergeAttributes(), there is a
similar but separate loop that merges the new local column definition
with the combination of the inheritance parents established in the
first loop. That comparison is already ColumnDef-vs-ColumnDef. With
this change, both of these can use similar-looking logic. (A future
project might be to extract these two sets of code into a common
routine that encodes all the knowledge of whether two column
definitions are compatible. But this isn't currently straightforward
because we want to give different error messages in the two cases.)
Furthermore, by avoiding the use of Form_pg_attribute here, we make it
easier to make changes in the pg_attribute layout without having to
worry about the local needs of tablecmds.c.
Because MergeAttributes() is hugely long, it's sometimes hard to know
where in the function you are currently looking. To help with that, I
also renamed some variables to make it clearer where you are currently
looking. The first look is "prev" vs. "new", the second loop is "inh"
vs. "new".
Discussion:
https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e...@eisentraut.org
---
src/backend/commands/tablecmds.c | 198 ++++++++++++++++---------------
1 file changed, 102 insertions(+), 96 deletions(-)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 2a56a4357c9..04e674bbdae 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -2704,7 +2704,8 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
parent_attno - 1);
char *attributeName = NameStr(attribute->attname);
int exist_attno;
- ColumnDef *def;
+ ColumnDef *newdef;
+ ColumnDef *savedef;
/*
* Ignore dropped columns in the parent.
@@ -2713,14 +2714,38 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
continue; /* leave
newattmap->attnums entry as zero */
/*
- * Does it conflict with some previously inherited
column?
+ * Create new column definition
+ */
+ newdef = makeColumnDef(attributeName,
attribute->atttypid,
+
attribute->atttypmod, attribute->attcollation);
+ newdef->storage = attribute->attstorage;
+ newdef->generated = attribute->attgenerated;
+ if (CompressionMethodIsValid(attribute->attcompression))
+ newdef->compression =
+
pstrdup(GetCompressionMethodName(attribute->attcompression));
+
+ /*
+ * Regular inheritance children are independent enough
not to
+ * inherit identity columns. But partitions are
integral part
+ * of a partitioned table and inherit identity column.
+ */
+ if (is_partition)
+ newdef->identity = attribute->attidentity;
+
+ /*
+ * Does it match some previously considered column from
another
+ * parent?
*/
exist_attno = findAttrByName(attributeName,
inh_columns);
if (exist_attno > 0)
{
- Oid defTypeId;
- int32 deftypmod;
- Oid defCollId;
+ ColumnDef *prevdef;
+ Oid prevtypeid,
+ newtypeid;
+ int32 prevtypmod,
+ newtypmod;
+ Oid prevcollid,
+ newcollid;
/*
* Partitions have only one parent and have no
column
@@ -2734,68 +2759,61 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
ereport(NOTICE,
(errmsg("merging multiple
inherited definitions of column \"%s\"",
attributeName)));
- def = (ColumnDef *) list_nth(inh_columns,
exist_attno - 1);
+ prevdef = list_nth_node(ColumnDef, inh_columns,
exist_attno - 1);
/*
* Must have the same type and typmod
*/
- typenameTypeIdAndMod(NULL, def->typeName,
&defTypeId, &deftypmod);
- if (defTypeId != attribute->atttypid ||
- deftypmod != attribute->atttypmod)
+ typenameTypeIdAndMod(NULL, prevdef->typeName,
&prevtypeid, &prevtypmod);
+ typenameTypeIdAndMod(NULL, newdef->typeName,
&newtypeid, &newtypmod);
+ if (prevtypeid != newtypeid || prevtypmod !=
newtypmod)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("inherited
column \"%s\" has a type conflict",
attributeName),
errdetail("%s versus
%s",
-
format_type_with_typemod(defTypeId,
-
deftypmod),
-
format_type_with_typemod(attribute->atttypid,
-
attribute->atttypmod))));
+
format_type_with_typemod(prevtypeid, prevtypmod),
+
format_type_with_typemod(newtypeid, newtypmod))));
/*
* Must have the same collation
*/
- defCollId = GetColumnDefCollation(NULL, def,
defTypeId);
- if (defCollId != attribute->attcollation)
+ prevcollid = GetColumnDefCollation(NULL,
prevdef, prevtypeid);
+ newcollid = GetColumnDefCollation(NULL, newdef,
newtypeid);
+ if (prevcollid != newcollid)
ereport(ERROR,
(errcode(ERRCODE_COLLATION_MISMATCH),
errmsg("inherited
column \"%s\" has a collation conflict",
attributeName),
errdetail("\"%s\"
versus \"%s\"",
-
get_collation_name(defCollId),
-
get_collation_name(attribute->attcollation))));
+
get_collation_name(prevcollid),
+
get_collation_name(newcollid))));
/*
* Copy/check storage parameter
*/
- if (def->storage == 0)
- def->storage = attribute->attstorage;
- else if (def->storage != attribute->attstorage)
+ if (prevdef->storage == 0)
+ prevdef->storage = newdef->storage;
+ else if (prevdef->storage != newdef->storage)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("inherited
column \"%s\" has a storage parameter conflict",
attributeName),
errdetail("%s versus
%s",
-
storage_name(def->storage),
-
storage_name(attribute->attstorage))));
+
storage_name(prevdef->storage),
+
storage_name(newdef->storage))));
/*
* Copy/check compression parameter
*/
- if
(CompressionMethodIsValid(attribute->attcompression))
- {
- const char *compression =
-
GetCompressionMethodName(attribute->attcompression);
-
- if (def->compression == NULL)
- def->compression =
pstrdup(compression);
- else if (strcmp(def->compression,
compression) != 0)
- ereport(ERROR,
-
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("column
\"%s\" has a compression method conflict",
-
attributeName),
- errdetail("%s
versus %s", def->compression, compression)));
- }
+ if (prevdef->compression == NULL)
+ prevdef->compression =
newdef->compression;
+ else if (strcmp(prevdef->compression,
newdef->compression) != 0)
+ ereport(ERROR,
+
(errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("column \"%s\"
has a compression method conflict",
+
attributeName),
+ errdetail("%s versus
%s", prevdef->compression, newdef->compression)));
/*
* In regular inheritance, columns in the
parent's primary key
@@ -2826,12 +2844,12 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
if (bms_is_member(parent_attno, nncols) ||
bms_is_member(parent_attno -
FirstLowInvalidHeapAttributeNumber,
pkattrs))
- def->is_not_null = true;
+ newdef->is_not_null = true;
/*
* Check for GENERATED conflicts
*/
- if (def->generated != attribute->attgenerated)
+ if (prevdef->generated != newdef->generated)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("inherited
column \"%s\" has a generation conflict",
@@ -2841,43 +2859,30 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
* Default and other constraints are handled
below
*/
- def->inhcount++;
- if (def->inhcount < 0)
+ prevdef->inhcount++;
+ if (prevdef->inhcount < 0)
ereport(ERROR,
errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("too many
inheritance parents"));
newattmap->attnums[parent_attno - 1] =
exist_attno;
+
+ /* remember for default processing below */
+ savedef = prevdef;
}
else
{
/*
* No, create a new inherited column
*/
- def = makeColumnDef(attributeName,
attribute->atttypid,
-
attribute->atttypmod, attribute->attcollation);
- def->inhcount = 1;
- def->is_local = false;
+ newdef->inhcount = 1;
+ newdef->is_local = false;
/* mark attnotnull if parent has it and it's
not NO INHERIT */
if (bms_is_member(parent_attno, nncols) ||
bms_is_member(parent_attno -
FirstLowInvalidHeapAttributeNumber,
pkattrs))
- def->is_not_null = true;
- def->storage = attribute->attstorage;
- def->generated = attribute->attgenerated;
-
- /*
- * Regular inheritance children are independent
enough not to
- * inherit identity columns. But partitions
are integral part
- * of a partitioned table and inherit identity
column.
- */
- if (is_partition)
- def->identity = attribute->attidentity;
-
- if
(CompressionMethodIsValid(attribute->attcompression))
- def->compression =
-
pstrdup(GetCompressionMethodName(attribute->attcompression));
- inh_columns = lappend(inh_columns, def);
+ newdef->is_not_null = true;
+ inh_columns = lappend(inh_columns, newdef);
newattmap->attnums[parent_attno - 1] =
++child_attno;
/*
@@ -2906,6 +2911,9 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
nnconstraints = lappend(nnconstraints,
nn);
}
+
+ /* remember for default processing below */
+ savedef = newdef;
}
/*
@@ -2927,7 +2935,7 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
* all the inherited default expressions for
the moment.
*/
inherited_defaults =
lappend(inherited_defaults, this_default);
- cols_with_defaults =
lappend(cols_with_defaults, def);
+ cols_with_defaults =
lappend(cols_with_defaults, savedef);
}
}
@@ -3065,17 +3073,17 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
newcol_attno++;
/*
- * Does it conflict with some previously inherited
column?
+ * Does it match some inherited column?
*/
exist_attno = findAttrByName(attributeName,
inh_columns);
if (exist_attno > 0)
{
- ColumnDef *def;
- Oid defTypeId,
- newTypeId;
- int32 deftypmod,
+ ColumnDef *inhdef;
+ Oid inhtypeid,
+ newtypeid;
+ int32 inhtypmod,
newtypmod;
- Oid defcollid,
+ Oid inhcollid,
newcollid;
/*
@@ -3095,77 +3103,75 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
ereport(NOTICE,
(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(inh_columns,
exist_attno - 1);
+ inhdef = list_nth_node(ColumnDef, inh_columns,
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)
+ typenameTypeIdAndMod(NULL, inhdef->typeName,
&inhtypeid, &inhtypmod);
+ typenameTypeIdAndMod(NULL, newdef->typeName,
&newtypeid, &newtypmod);
+ if (inhtypeid != newtypeid || inhtypmod !=
newtypmod)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\"
has a type conflict",
attributeName),
errdetail("%s versus
%s",
-
format_type_with_typemod(defTypeId,
-
deftypmod),
-
format_type_with_typemod(newTypeId,
-
newtypmod))));
+
format_type_with_typemod(inhtypeid, inhtypmod),
+
format_type_with_typemod(newtypeid, newtypmod))));
/*
* Must have the same collation
*/
- defcollid = GetColumnDefCollation(NULL, def,
defTypeId);
- newcollid = GetColumnDefCollation(NULL, newdef,
newTypeId);
- if (defcollid != newcollid)
+ inhcollid = GetColumnDefCollation(NULL, inhdef,
inhtypeid);
+ newcollid = GetColumnDefCollation(NULL, newdef,
newtypeid);
+ if (inhcollid != newcollid)
ereport(ERROR,
(errcode(ERRCODE_COLLATION_MISMATCH),
errmsg("column \"%s\"
has a collation conflict",
attributeName),
errdetail("\"%s\"
versus \"%s\"",
-
get_collation_name(defcollid),
+
get_collation_name(inhcollid),
get_collation_name(newcollid))));
/*
* Identity is never inherited. The new column
can have an
* identity definition, so we always just take
that one.
*/
- def->identity = newdef->identity;
+ inhdef->identity = newdef->identity;
/*
* Copy storage parameter
*/
- if (def->storage == 0)
- def->storage = newdef->storage;
- else if (newdef->storage != 0 && def->storage
!= newdef->storage)
+ if (inhdef->storage == 0)
+ inhdef->storage = newdef->storage;
+ else if (newdef->storage != 0 &&
inhdef->storage != newdef->storage)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\"
has a storage parameter conflict",
attributeName),
errdetail("%s versus
%s",
-
storage_name(def->storage),
+
storage_name(inhdef->storage),
storage_name(newdef->storage))));
/*
* Copy compression parameter
*/
- if (def->compression == NULL)
- def->compression = newdef->compression;
+ if (inhdef->compression == NULL)
+ inhdef->compression =
newdef->compression;
else if (newdef->compression != NULL)
{
- if (strcmp(def->compression,
newdef->compression) != 0)
+ if (strcmp(inhdef->compression,
newdef->compression) != 0)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column
\"%s\" has a compression method conflict",
attributeName),
- errdetail("%s
versus %s", def->compression, newdef->compression)));
+ errdetail("%s
versus %s", inhdef->compression, newdef->compression)));
}
/*
* Merge of not-null constraints = OR 'em
together
*/
- def->is_not_null |= newdef->is_not_null;
+ inhdef->is_not_null |= newdef->is_not_null;
/*
* Check for conflicts related to generated
columns.
@@ -3182,18 +3188,18 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
* it results in being able to override the
generation
* expression via UPDATEs through the parent.)
*/
- if (def->generated)
+ if (inhdef->generated)
{
if (newdef->raw_default &&
!newdef->generated)
ereport(ERROR,
(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
errmsg("column
\"%s\" inherits from generated column but specifies default",
-
def->colname)));
+
inhdef->colname)));
if (newdef->identity)
ereport(ERROR,
(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
errmsg("column
\"%s\" inherits from generated column but specifies identity",
-
def->colname)));
+
inhdef->colname)));
}
else
{
@@ -3201,7 +3207,7 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
ereport(ERROR,
(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
errmsg("child
column \"%s\" specifies generation expression",
-
def->colname),
+
inhdef->colname),
errhint("A
child table column cannot be generated unless its parent column is.")));
}
@@ -3210,12 +3216,12 @@ MergeAttributes(List *columns, const List *supers, char
relpersistence,
*/
if (newdef->raw_default != NULL)
{
- def->raw_default = newdef->raw_default;
- def->cooked_default =
newdef->cooked_default;
+ inhdef->raw_default =
newdef->raw_default;
+ inhdef->cooked_default =
newdef->cooked_default;
}
/* Mark the column as locally defined */
- def->is_local = true;
+ inhdef->is_local = true;
}
else
{
--
2.43.0
