Sequential Scans

Hi all, we are struggeling here with a system reporting lots of sequential scans on specific tables (actually on two tables, which have a number of rows > 100000, this is our check ) according to the sysptprof table in sysmaster. BUT - when we activate explain on all the connections, we do not see any entry which refers to the table with a SEQUENTIAL output. How can we detect which statement is causing the entries ? Or is the information in the sysptprof table not correct ? IDS 11.70FC7 on Linux Any ideas ? Thanks in advance for your opinion. Marcus Haarmann

Do you have procedures that may run full scans on those tables? You may try to activate the SQL Trace facility... Regards. On Thu, May 2, 2013 at 11:02 AM, Marcus Haarmann <marcus.haarmann@midoco.de>wrote: > Hi all, > > we are struggeling here with a system reporting lots of sequential scans on > specific tables > (actually on two tables, which have a number of rows > 100000, this is our > check ) > according to the sysptprof table in sysmaster. > BUT - when we activate explain on all the connections, we do not see any > entry > which refers > to the table with a SEQUENTIAL output. > How can we detect which statement is causing the entries ? Or is the > information > in the sysptprof table not correct ? > > IDS 11.70FC7 on Linux > > Any ideas ? > > Thanks in advance for your opinion. > > Marcus Haarmann > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently... --20cf307d0284956bdc04dbb977b2

It should be accurate. Try turning on SQLTRACE to medium level and either turn on the SQL history sensor in OAT or Sentinel or poll sysmaster:syssqltrace manually periodically looking for queries that reference that table. Once you have captured the queries and any values supplied to replaceable parameters you can run them in dbaccess with SET EXPLAIN turned on and see what's happening. Setting explain sessions already running doesn't get you anything if the statements were already prepared! Art Art S. Kagel Advanced DataTools (www.advancedatatools.com) Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Advanced DataTools, the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Thu, May 2, 2013 at 6:02 AM, Marcus Haarmann <marcus.haarmann@midoco.de>wrote: > Hi all, > > we are struggeling here with a system reporting lots of sequential scans on > specific tables > (actually on two tables, which have a number of rows > 100000, this is our > check ) > according to the sysptprof table in sysmaster. > BUT - when we activate explain on all the connections, we do not see any > entry > which refers > to the table with a SEQUENTIAL output. > How can we detect which statement is causing the entries ? Or is the > information > in the sysptprof table not correct ? > > IDS 11.70FC7 on Linux > > Any ideas ? > > Thanks in advance for your opinion. > > Marcus Haarmann > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --001a11c20c9a1c7ad604dbb99f53