Re: Question about Extents

Carlos Novo Negrillo wrote: > > I'm working with Online 7.2. > > I've seen that when Informix alocates a new extent for a table, > and later that table is erased ( not dropped ), the space previosly > allocated is not freed ... Correct. > How can I make online to free that space for being allocated for > other table/s when needed ? Reorganize that table if it is not going to be growing again for a while. See below. > When online alocates an extent into a coocked chunk ... is it really > contiguous in disk ? NO IT IS NOT. That is one of the strongest reasons to use RAW files. BTW despite the claims of others my benchmarks have always shown that raw chunks are SIGNIFICANTLY faster than cooked. Just the fact that Informix runs cooked files in AutoSync mode will slow them considerably. > another Question : > > How can I compact the tables and indexes ? Adjust the table's NEXT SIZE to make sure that the reorged table will only have one or two extents then use the sytax: ALTER FRAGMENT ON <table> INIT IN <dbspace>; to reorganize and compress the table. This is the fastest way to compress a table. If you want a better fill factor in your indexes than that which is recorded in the ONCONFIG file you'll have to drop the indexes before reorging and recreate them by hand with an explicit FILLFACTOR option of say 100 (FULL) or 99 (room for one key on each node). Art S. Kagel