The MANOPT setting stands for manual optomization of query processing. Normally it is OFF so that means that when you submit a query to R:base, R:base then looks at your query and rearranges the tables and decides which indexes it should use to do the query to get the best performance. Normally the optomizer does a very good job, but there are times when it makes bad decisions about how to do queries. There are some values for each index in the sys_indexes table that the system computes when you do a reload that keeps track of good indexes from bad indexes. A good index has a unique value (primary key) in every row where a bad index is like Karen's code field below where there are lots of duplicates. I am not saying that the code field index should not be there, but other indexes are better to use when available. The sys_indexes table has the fields SYS_DUP_FACTOR and SYS_ADJ_FACTOR that are computed when you do a reload.
If you don't do a reload very often, the values for these factors get out of sync to what the data is so that then the optomizer is more likely to make bad decisions as to which indexes to use. So, if you turn MANOPT ON, you will have to be on your toes because this means you will have to manually optomize every query, and personally I am too lazy. Once in a while I will turn it on to do one query and then be sure to turn it back off. Troy ===== Original Message from [EMAIL PROTECTED] at 4/15/02 7:30 am >Does the SETting for "MANOPT" have any role here? Isn't there also a means >to analyze query processing in RB? > >With that message about '<>', I'll be checking some code that I wish would >run faster. > >Later, >Steve in Memphis > >> -----Original Message----- >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On >> Behalf Of Alastair Burr >> Sent: Saturday, April 13, 2002 9:39 AM >> To: [EMAIL PROTECTED] >> Subject: Re: Using index is slower >> >> >> Karen / Tom >> >> If the table(s) on which the view is based are indexed then >> _maybe_ there is >> some sort of conflict if R:Base tries to index everything and it >> just works >> faster the simpler the query is. >> >> It would be nice to know from "the experts", though. >> >> Regards, Alastair. >> >> ----- Original Message ----- >> From: "tellef" <[EMAIL PROTECTED]> >> To: <[EMAIL PROTECTED]> >> Sent: Saturday, April 13, 2002 2:25 PM >> Subject: Re: Using index is slower >> >> >> > Tom: >> > >> > >OK Karen. I know I under slept last night and maybe that's the reason >> > >your good advice is not hitting the meat... ...are unindexed queries >> > >against views faster? >> > >> > >If so, why? >> > >> > Got me hanging!!! I have no idea! And I don't think we can make >> > a blanket statement just based on this experience. The only difference >> > I could see between the fast statement and the never-ending statement >> > was that the fast statement wasn't using an index. So I forced the >> > slow one to not use an index by using the parenthesis, and all of a >> > sudden it was fast. >> > >> > I would love to hear from someone why it would be faster without >> > an index. In the meantime I'd suggest that anyone who has a really >> > slow view and you're selecting based on an indexed column, go ahead >> > and try an un-indexed search for the heck of it! >> > >> > >> > Karen >> > >> > >> > >> > ================================================ >> > TO SEE MESSAGE POSTING GUIDELINES: >> > Send a plain text email to [EMAIL PROTECTED] >> > In the message body, put just two words: INTRO rbase-l >> > ================================================ >> > TO UNSUBSCRIBE: send a plain text email to [EMAIL PROTECTED] >> > In the message body, put just two words: UNSUBSCRIBE rbase-l >> > ================================================ >> > TO SEARCH ARCHIVES: >> > http://www.mail-archive.com/rbase-l%40sonetmail.com/ >> >> ================================================ >> TO SEE MESSAGE POSTING GUIDELINES: >> Send a plain text email to [EMAIL PROTECTED] >> In the message body, put just two words: INTRO rbase-l >> ================================================ >> TO UNSUBSCRIBE: send a plain text email to [EMAIL PROTECTED] >> In the message body, put just two words: UNSUBSCRIBE rbase-l >> ================================================ >> TO SEARCH ARCHIVES: >> http://www.mail-archive.com/rbase-l%40sonetmail.com/ >> > >================================================ >TO SEE MESSAGE POSTING GUIDELINES: >Send a plain text email to [EMAIL PROTECTED] >In the message body, put just two words: INTRO rbase-l >================================================ >TO UNSUBSCRIBE: send a plain text email to [EMAIL PROTECTED] >In the message body, put just two words: UNSUBSCRIBE rbase-l >================================================ >TO SEARCH ARCHIVES: >http://www.mail-archive.com/rbase-l%40sonetmail.com/ ================================================ TO SEE MESSAGE POSTING GUIDELINES: Send a plain text email to [EMAIL PROTECTED] In the message body, put just two words: INTRO rbase-l ================================================ TO UNSUBSCRIBE: send a plain text email to [EMAIL PROTECTED] In the message body, put just two words: UNSUBSCRIBE rbase-l ================================================ TO SEARCH ARCHIVES: http://www.mail-archive.com/rbase-l%40sonetmail.com/
