I think part 1 is a great idea.
Having to generate stats using a separate process outside of the database
has always been a nuisance.
The sooner we can do it using SQL the better.
Lin
Internet
schendel@kbcom
puter.com To
info-ingres (AT) kettleriverconsulting (DOT) com
Sent by: cc
info-ingres-bo
unces@kettleri Subject
verconsulting. Re: [Info-Ingres] Enhancement to Ingres
com Statistics Generation and Storage
26/11/2009
13:40
Please respond
to
info-ingres@ke
ttleriverconsu
lting.com
On Nov 26, 2009, at 5:39 AM, rthdavid wrote:
Quote:
Part 1:-
....
MODIFY <table> TO <structure> WITH <clause>, STATISTICS = (flags);
CREATE [unique] INDEX <index> ON <table> (column list) WITH <clause>,
STATISTICS = (flags);
This should significantly reduce the end-to-end processing time
because the base table is only scanned once. |
It would also get the DBMS server itself involved in statistics
creation, opening the door to auto-creation of stats. Not a bad
thing.
However, I'm not sure how much this would reduce overall
runtime. Part of the issue with stats creation is that you have
to summarize the table a bunch of different ways. The base
table scan time may not be the major factor. I've never
really looked at how optimizedb time breaks down, though.
Quote:
Part 2:-
I would also like to see statistics moved to 's-tabs' (a bit like 'e-
tabs' but for statistics rather than long objects) that exist
alongside a base table.
I appreciate that this would be a major change to how Ingres generates
and uses statistics (OPF), but it would eliminate pressure on system
catalogs, improve concurrency and provide a mechanism of having
statistics on sub-table objects like individual table partitions? |
I don't think I follow this one entirely. The proliferation of tables
would add to DMF memory pressure for the TCB's and S-table
pages, and clog up the DMF cache lists. The existing stats
tables are capable of per-partition stats, but neither RDF nor
the optimizer would have any idea what to do with them.
I'd suggest instead looking at removing the control lock taken
when stats are updated -- it's not really necessary, and is the
main concurrency bottleneck.
Karl
_______________________________________________
Info-Ingres mailing list
Info-Ingres (AT) kettleriverconsulting (DOT) com
http://ext-cando.kettleriverconsulti...fo/info-ingres
__________________________________________________ _________
This communication is confidential, may be privileged and is meant only forthe intended recipient. If you are not the intended recipient, please notify the sender by reply and delete the message from your system. Any unauthorised dissemination, distribution or copying hereof is prohibited.
BNP Paribas Trust Corporation UK Limited, BNP Paribas UK Limited, BNP Paribas Commodity Futures Limited, BNP Paribas Asset Management UK Limited and Investment Fund Services Limited are authorised and regulated by the Financial Services Authority.
BNP Paribas London Branch and BNP Paribas Wealth Management London Branch are authorised by the CECEI and supervised by the Commission Bancaire.
BNP Paribas London Branch is authorised and subject to limited regulation by the Financial Services Authority. Details about the extent of our authorisation and regulation by the Financial Services Authority are available from us on request. BNP Paribas is also a member of the London Stock Exchange.
BNP Paribas Wealth Management London Branch is subject to limited regulation by the Financial Services Authority. Details about the extent of our authorisation and regulation by the Financial Services Authority are availablefrom us on request.
BNP Paribas Securities Services London Branch is authorised by the CECEI and supervised by the AMF, and subject to limited regulation by the FinancialServices Authority. Details on the extent of our regulation by the Financial Services Authority are available from us on request. BNP Paribas Securities Services is also a member of the London Stock Exchange.
BNP Paribas Trust Corporation UK Limited is registered in England and Wales(registered no. 4042668) at registered office 55 Moorgate, London EC2R 6PA.
BNP Paribas UK Limited is registered in England and Wales (registered no. 1488108) at registered office 10 Harewood Avenue, London NW1 6AA.
BNP Paribas Commodity Futures Limited is registered in England and Wales (registered no. 2391477) at registered office 10 Harewood Avenue, London NW1 6AA.
BNP Paribas Asset Management UK Limited is registered in England and Wales (registered no. 2474627) at registered office 10 Harewood Avenue, London NW1 6AA.
Investment Fund Services Limited is registered in England and Wales (registered no. 6110770) at registered office 55 Moorgate, London EC2R 6PA.
BNP Paribas London Branch is registered in England and Wales (registered no.. FC13447) at registered office 10 Harewood Avenue, London NW1 6AA.
BNP Paribas Wealth Management London Branch is registered in England and Wales (registered no. FC023926) at registered office 10 Harewood Avenue, London NW1 6AA.
BNP Paribas Securities Services London Branch is registered in England and Wales (registered no. BR006393) at registered office 55 Moorgate, London, EC2R 6PA.
BNP Paribas Lease Group Plc is registered in England and Wales (registeredno. 2341989) at registered office Northern Cross, Basing View, Basingstoke, Hampshire RG21 4HL.
__________________________________________________ __________
BNP Paribas is proud to support the Royal Academy of Arts in their presentation of ‘Wild Thing: Epstein, Gaudier-Brzeska, Gill’ in theSackler Wing of Galleries from 24 October 2009 to 24 January 2010.