Re: pg primary key bug? - Mailing list pgsql-sql
From | pginfo |
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Subject | Re: pg primary key bug? |
Date | |
Msg-id | 421AC251.7060806@t1.unisoftbg.com Whole thread Raw |
In response to | Re: pg primary key bug? (Richard_D_Levine@raytheon.com) |
Responses |
Re: pg primary key bug?
|
List | pgsql-sql |
Hi Tom,<br /><br /> Tom Lane wrote:<br /><blockquote cite="mid3293.1109026294@sss.pgh.pa.us" type="cite"><pre wrap="">pginfo<a class="moz-txt-link-rfc2396E" href="mailto:pginfo@t1.unisoftbg.com"><pginfo@t1.unisoftbg.com></a>writes: </pre><blockquote type="cite"><pre wrap="">sorry,but we have the case number 3 in with the same problem. Also this time we do not find any linux box crash nor pg stop or restart. </pre></blockquote><pre wrap=""> Hmm, well there's *something* mighty curious about the history of this table. The xmin values span a range of almost 400,000 transactions and yet the oids are twenty-three consecutive values. Is this the only table you've inserted into during the last 400K transactions? </pre></blockquote> No.<br /><blockquote cite="mid3293.1109026294@sss.pgh.pa.us"type="cite"><pre wrap=""> It's also odd that there's so much empty space (only 37 rows in 60 pages). It's hard to see how that could be unless there were many updates on the table, but judging from the name and contents of the table I can hardly see a reason for lots of updates. How is this table used exactly?</pre></blockquote> In this table we store the last value for the ID of part from other tables.<br /> For eachtable we have one constant in this table. We are using the table as sequence.<br /> For Example if we nee to insert thenext record in some table we make:<br /> select constvalue from a_constants_str where constname ='...' for update;<br/> increase the value and make <br /> update a_constants_str set constvalue= (new value) where...<br /><br />It is not so easy as I described, but in general this is the case.<br /> Al this is connected with replications and datasyncronisation and so on.<br /><br /><blockquote cite="mid3293.1109026294@sss.pgh.pa.us" type="cite"><pre wrap=""> Doyou do UPDATEs on it?</pre></blockquote> Yes, see the description.<br /><blockquote cite="mid3293.1109026294@sss.pgh.pa.us"type="cite"><pre wrap=""> DELETEs?</pre></blockquote> No, never.<br /><blockquotecite="mid3293.1109026294@sss.pgh.pa.us" type="cite"><pre wrap=""> SELECT FOR UPDATE?</pre></blockquote> Yes.<br/><blockquote cite="mid3293.1109026294@sss.pgh.pa.us" type="cite"><pre wrap=""> Do you do VACUUM, or VACUUM FULL, or both?</pre></blockquote> Only vacuum full analyze once per day.<br /> Also once per4h pg_dump (for pg 7.x we do not have any chance to restore data without full dump. With 8.0 we will test the ne solutionand stop to make pg_dump.<br /><br /> We have > 200 relative big installs for this ERP and all are using pg.<br/> For the last 3 y. we have one time data corruption and in this 3 cases problem with pkey's.<br /> All the time pgis working relative well .<br /><br /> regards,<br /> ivan.<br /><blockquote cite="mid3293.1109026294@sss.pgh.pa.us" type="cite"><prewrap=""> regards, tom lane </pre></blockquote><br />