Limit on multi-field indexes?
Am I correct in believing that there is a limit of seven columns in a
multi-filed index?
If so, is it possible to increase this limit (to at least eight) ?
Cheers and thanks,
Stephen.
========================================================================
Stephen Davies Consulting scldad@sdc.com.au
Adelaide, South Australia. Voice: 61-8-82728863
Computing & Network solutions. Fax: 61-8-82741015
Am I correct in believing that there is a limit of seven columns in a
multi-filed index?If so, is it possible to increase this limit (to at least eight) ?
Cheers and thanks,
Not easily. The columns are stored in an int28 column, that holds 8
two-byte integer. We would have to change that to a larger field. Very
few people have asked for this.
--
Bruce Momjian | 830 Blythe Avenue
maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026
http://www.op.net/~candle | (610) 353-9879(w)
+ If your life is a hard drive, | (610) 853-3000(h)
+ Christ can be your backup. |Am I correct in believing that there is a limit of seven columns in a
multi-filed index?If so, is it possible to increase this limit (to at least eight) ?
Cheers and thanks,
Not easily. The columns are stored in an int28 column, that holds 8
two-byte integer. We would have to change that to a larger field. Very
few people have asked for this.
Getting desperate here.
If it holds 8 integers, why can't I have 8 columns in a multi-field index?
I am currently writing a tool to replicate any database to a PostgreSQL mirror
and the very first customer for this tool has several tables with 8 fields in
their primary key. Sod's Law:-((
Cheers and thanks,
Stephen.
========================================================================
Stephen Davies Consulting scldad@sdc.com.au
Adelaide, South Australia. Voice: 61-8-82728863
Computing & Network solutions. Fax: 61-8-82741015
What do I use to read postgres's log, pg_log??? Please reply to my email
if possible.
Thanks
-jeremy
Thus spake Stephen Davies
I am currently writing a tool to replicate any database to a PostgreSQL mirror
and the very first customer for this tool has several tables with 8 fields in
their primary key. Sod's Law:-((
Could that database be badly in need of a redesign? :-)
--
D'Arcy J.M. Cain <darcy@{druid|vex}.net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 424 2871 (DoD#0082) (eNTP) | what's for dinner.Am I correct in believing that there is a limit of seven columns in a
multi-filed index?If so, is it possible to increase this limit (to at least eight) ?
Cheers and thanks,
Not easily. The columns are stored in an int28 column, that holds 8
two-byte integer. We would have to change that to a larger field. Very
few people have asked for this.Getting desperate here.
If it holds 8 integers, why can't I have 8 columns in a multi-field index?
I am currently writing a tool to replicate any database to a PostgreSQL mirror
and the very first customer for this tool has several tables with 8 fields in
their primary key. Sod's Law:-((
There is no field in pg_index to determine the number of fields in the
index, so it scans pg_index.indkey until it hits a 0. Now, I suppose we
could change the code so it goes through indkey until it gets a 0, or
reaches the eighth entry.
--
Bruce Momjian | 830 Blythe Avenue
maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026
http://www.op.net/~candle | (610) 353-9879(w)
+ If your life is a hard drive, | (610) 853-3000(h)
+ Christ can be your backup. |If it holds 8 integers, why can't I have 8 columns in a multi-field index?
I am currently writing a tool to replicate any database to a PostgreSQL mirror
and the very first customer for this tool has several tables with 8 fields in
their primary key. Sod's Law:-((
OK, I am committing changes which will allow 8-key indexes, rather than
just seven. Please test this at your convenience.
--
Bruce Momjian | 830 Blythe Avenue
maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026
http://www.op.net/~candle | (610) 353-9879(w)
+ If your life is a hard drive, | (610) 853-3000(h)
+ Christ can be your backup. |If it holds 8 integers, why can't I have 8 columns in a multi-field index?
I am currently writing a tool to replicate any database to a PostgreSQL mirror
and the very first customer for this tool has several tables with 8 fields in
their primary key. Sod's Law:-((OK, I am committing changes which will allow 8-key indexes, rather than
just seven. Please test this at your convenience.
Good on ya Bruce!!
(Traditional Aussie saying ;-) )
Thank you very much. Where might I find the patch?
Cheers and thanks,
Stephen.
========================================================================
Stephen Davies Consulting scldad@sdc.com.au
Adelaide, South Australia. Voice: 61-8-82728863
Computing & Network solutions. Fax: 61-8-82741015
If it holds 8 integers, why can't I have 8 columns in a multi-field index?
I am currently writing a tool to replicate any database to a PostgreSQL mirror
and the very first customer for this tool has several tables with 8 fields in
their primary key. Sod's Law:-((OK, I am committing changes which will allow 8-key indexes, rather than
just seven. Please test this at your convenience.Good on ya Bruce!!
(Traditional Aussie saying ;-) )
Thank you very much. Where might I find the patch?
You have to get involved in the 6.4 beta by joining the hackers list,
and/or get a snapshot from the ftp site that has a date after today's
date.
--
Bruce Momjian | 830 Blythe Avenue
maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026
http://www.op.net/~candle | (610) 353-9879(w)
+ If your life is a hard drive, | (610) 853-3000(h)
+ Christ can be your backup. |