Re: [HACKERS] pg_buffercache causes assertion failure - Mailing list pgsql-patches

Mark Kirkwood wrote:
> Mark Kirkwood wrote:
>
>>
>> I couldn't use int4 as the underlying datatype is unsigned int (not
>> available as exposed Pg type). However, using int8 sounds promising
>> (is int8 larger than unsigned int on 64-bit platforms?).
>
>
> Blocknumber is defined as uint32 in block.h - so should always be safe
> to represent as an int8 I am thinking.
>
> I will look at patching pg_buffercache, changing numeric -> int8 for the
> relblocknumber column. This seems a tidier solution than using numeric,
> and loses the numeric overhead.

This patch changes the use of numeric to int8 to represent the
relblocknumber column.

regards

Mark

diff -Ncar pgsql.orig/contrib/pg_buffercache/README.pg_buffercache pgsql/contrib/pg_buffercache/README.pg_buffercache
*** pgsql.orig/contrib/pg_buffercache/README.pg_buffercache    Tue May 31 11:02:41 2005
--- pgsql/contrib/pg_buffercache/README.pg_buffercache    Tue May 31 11:05:48 2005
***************
*** 66,78 ****
     relfilenode    | oid     |
     reltablespace  | oid     |
     reldatabase    | oid     |
!    relblocknumber | numeric |
     isdirty        | boolean |
    View definition:
     SELECT p.bufferid, p.relfilenode, p.reltablespace, p.reldatabase,
            p.relblocknumber, p.isdirty
       FROM pg_buffercache_pages() p(bufferid integer, relfilenode oid,
!      reltablespace oid, reldatabase oid, relblocknumber numeric(10,0),
       isdirty boolean);

    regression=# SELECT c.relname, count(*) AS buffers
--- 66,78 ----
     relfilenode    | oid     |
     reltablespace  | oid     |
     reldatabase    | oid     |
!    relblocknumber | bigint  |
     isdirty        | boolean |
    View definition:
     SELECT p.bufferid, p.relfilenode, p.reltablespace, p.reldatabase,
            p.relblocknumber, p.isdirty
       FROM pg_buffercache_pages() p(bufferid integer, relfilenode oid,
!      reltablespace oid, reldatabase oid, relblocknumber bigint,
       isdirty boolean);

    regression=# SELECT c.relname, count(*) AS buffers
diff -Ncar pgsql.orig/contrib/pg_buffercache/pg_buffercache.sql.in pgsql/contrib/pg_buffercache/pg_buffercache.sql.in
*** pgsql.orig/contrib/pg_buffercache/pg_buffercache.sql.in    Tue May 31 11:02:41 2005
--- pgsql/contrib/pg_buffercache/pg_buffercache.sql.in    Tue May 31 09:15:03 2005
***************
*** 11,17 ****
  CREATE VIEW pg_buffercache AS
      SELECT P.* FROM pg_buffercache_pages() AS P
       (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,
!       relblocknumber numeric(10), isdirty bool);

  -- Don't want these to be available at public.
  REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC;
--- 11,17 ----
  CREATE VIEW pg_buffercache AS
      SELECT P.* FROM pg_buffercache_pages() AS P
       (bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,
!       relblocknumber int8, isdirty bool);

  -- Don't want these to be available at public.
  REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC;
diff -Ncar pgsql.orig/contrib/pg_buffercache/pg_buffercache_pages.c pgsql/contrib/pg_buffercache/pg_buffercache_pages.c
*** pgsql.orig/contrib/pg_buffercache/pg_buffercache_pages.c    Tue May 31 11:02:41 2005
--- pgsql/contrib/pg_buffercache/pg_buffercache_pages.c    Tue May 31 11:23:46 2005
***************
*** 93,99 ****
          TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
                                      OIDOID, -1, 0);
          TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relblockbumber",
!                                     NUMERICOID, -1, 0);
          TupleDescInitEntry(tupledesc, (AttrNumber) 6, "isdirty",
                                      BOOLOID, -1, 0);

--- 93,99 ----
          TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
                                      OIDOID, -1, 0);
          TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relblockbumber",
!                                     INT8OID, -1, 0);
          TupleDescInitEntry(tupledesc, (AttrNumber) 6, "isdirty",
                                      BOOLOID, -1, 0);