Thread: relID and tupleID

relID and tupleID

From
"S -"
Date:
Iam trying to figure out what value relID holds in postgresql. relID is 
present is struct LOCKTAG in LOCK.h.
And also, in src/backend/storage/lmgr/readme mentions  'tupleID", I can't 
find what tupleID represents and where its present in posgresql code
Thanks
-sumaira




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Re: relID and tupleID

From
Tom Lane
Date:
"S -" <nat_lazy@hotmail.com> writes:
> Iam trying to figure out what value relID holds in postgresql. relID is 
> present is struct LOCKTAG in LOCK.h.

pg_class OID of a table.

> And also, in src/backend/storage/lmgr/readme mentions  'tupleID", I can't 
> find what tupleID represents and where its present in posgresql code

Looks like someone separated tupleid into page number (objId.blkno) and
item number (offnum) to avoid having alignment padding inside the LOCKTAG
struct.
        regards, tom lane



Re: relID and tupleID

From
"S -"
Date:
in src/backend/storage/lmgr/readme
in the explanation of tag.objId
when it says blockId does it mean
tag.objId.blkno
in LOCKTAG struct in Lock.h ??


so actually the tuple id is comprised of:
Block Number objId.blkno AND OffsetNumber offnum ?

Thank you so much,
Sumaira





>From: Tom Lane <tgl@sss.pgh.pa.us>
>To: "S -" <nat_lazy@hotmail.com>
>CC: pgsql-hackers@postgresql.org
>Subject: Re: [HACKERS] relID and tupleID Date: Sat, 19 Apr 2003 01:49:10 
>-0400
>
>"S -" <nat_lazy@hotmail.com> writes:
> > Iam trying to figure out what value relID holds in postgresql. relID is
> > present is struct LOCKTAG in LOCK.h.
>
>pg_class OID of a table.
>
> > And also, in src/backend/storage/lmgr/readme mentions  'tupleID", I 
>can't
> > find what tupleID represents and where its present in posgresql code
>
>Looks like someone separated tupleid into page number (objId.blkno) and
>item number (offnum) to avoid having alignment padding inside the LOCKTAG
>struct.
>
>            regards, tom lane


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