Margus, > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] > Sent: Monday, 9 February 2004 10:23 p.m. > To: [EMAIL PROTECTED] > Subject: UV secondary index > > > Hello, > > I have distributed UV file with total size about 2.5Gb. > I made secondary index > CREATE. INDEX file field1 ... field6 > BUILD.INDEX file field1 ... field6 This syntax creates & builds six separate secondary index files, so that inserting a row in the main file will create probably between six and eighteen additional I/O operations to the multiple indices. Is this what you intended? If you actually wanted to create a single secondary index based on a concatenation of the first six fields, you need to create an I-type which does the concatenation, then index on the I-type. If you do need six separate secondary indices, maybe you need to look at where the index files are placed (different disk channel from main file,etc.)
Another possibility is that the data is very 'clumpy' on one or more index fields, so that a large proportion of the records share the same value for that index. When UV comes to add a value to the index, it has to scan through a huge set of identical values and then put the new occurrence at the end: this gets exponentially slower. If the shared value is <null>, then re-creating your index/indices with NO.NULLS will help. If it's not null (maybe it's a month number, so all records fall into only twelve distinct values?), then you need to find some way of creating a more-unique (e.g. month and day) indexable value. HTH Mike > > After that, rows inserting takes very long time. > (4000 rows. Server so busy, that other users can't do anything. > If I removed index then inserting process is OK, but I need this > index for reporting) > Is it normal in UniVerse? > How to avoid this problem? > I use UniVerse 9.5.2 on AIX 5.2 > > Thanks, > Margus Kandelin > The information contained in this Internet Email message is intended for the addressee only and may contain privileged information, but not necessarily the official views or opinions of the New Zealand Defence Force. If you are not the intended recipient you must not use, disclose, copy or distribute this message or the information in it. If you have received this message in error, please Email or telephone the sender immediately. -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
