Dbspace with 2 chunks

Hi, I have a dbspace with 2 chunks. The first chunk is almost full, the second has a lot of space. What will hapen when the first one is completaly full ? Informix will show a 0 on onstad -d command for this chunk ? Enviado desde mi iPhone

Maybe. It depends. If the first chunk has all of its remaining free space in a single extent of say 10KB there are three possibilities if a partition in that dbspace needs a new extent: 1. The requested extent is larger than 10KB 2. The requested extent is exactly 10KB 3. The requested extent is smaller than 10KB Informix uses a first fit algorithm to assign free space to an extent. So, listing free extents by their position on disk addressed by the chunk's ordinal position in the dbspace and its position within the chunk, the single 10K free extent in chunk 1 is listed before the free extents in chunk 2. Therefore this is what will happen to the three cases above: 1. Allocate the new extent from chunk 2. Chunk 1 still shows 10KB free. 2. Allocate the new extent from chunk 1. Chunk 1 shows 0KB free. 3. Allocate the new extent from chunk 1. Chunk 1 shows say 2KB free. If the free space in chunk 1 is itself fragmented into several small pieces the rules are the same, but only smaller extents will use the remaining free space in chunk 1. Art Art S. Kagel, President and Principal Consultant ASK Database Management www.askdbmgt.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 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 Wed, Mar 2, 2016 at 2:15 PM, Jorge Valenzuela <jorgervt@gmail.com> wrote: > Hi, > > I have a dbspace with 2 chunks. The first chunk is almost full, the second > has > a lot of space. What will hapen when the first one is completaly full ? > Informix will show a 0 on onstad -d command for this chunk ? > > Enviado desde mi iPhone > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --089e0139fddc0ae80c052d15fbca

Thanks for your explanation. Enviado desde mi iPhone > El 02/03/2016, a las 11:35 a.m., Art Kagel <art.kagel@gmail.com> escribió: > > Maybe. It depends. If the first chunk has all of its remaining free space > in a single extent of say 10KB there are three possibilities if a partition > in that dbspace needs a new extent: > > 1. The requested extent is larger than 10KB > > 2. The requested extent is exactly 10KB > > 3. The requested extent is smaller than 10KB > > Informix uses a first fit algorithm to assign free space to an extent. So, > listing free extents by their position on disk addressed by the chunk's > ordinal position in the dbspace and its position within the chunk, the > single 10K free extent in chunk 1 is listed before the free extents in > chunk 2. Therefore this is what will happen to the three cases above: > > 1. Allocate the new extent from chunk 2. Chunk 1 still shows 10KB free. > > 2. Allocate the new extent from chunk 1. Chunk 1 shows 0KB free. > > 3. Allocate the new extent from chunk 1. Chunk 1 shows say 2KB free. > > If the free space in chunk 1 is itself fragmented into several small pieces > the rules are the same, but only smaller extents will use the remaining > free space in chunk 1. > > Art > > Art S. Kagel, President and Principal Consultant > ASK Database Management > www.askdbmgt.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 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 Wed, Mar 2, 2016 at 2:15 PM, Jorge Valenzuela <jorgervt@gmail.com> wrote: >> >> Hi, >> >> I have a dbspace with 2 chunks. The first chunk is almost full, the second >> has >> a lot of space. What will hapen when the first one is completaly full ? >> Informix will show a 0 on onstad -d command for this chunk ? >> >> Enviado desde mi iPhone > ******************************************************************************* >> Forum Note: Use "Reply" to post a response in the discussion forum. > > --089e0139fddc0ae80c052d15fbca > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. >

Yes, "onstat -d" will show a 0 in the "free" column for the full chunk. -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Jorge Valenzuela Sent: Wednesday, March 02, 2016 12:16 PM To: ids@iiug.org Subject: Dbspace with 2 chunks [36692] Hi, I have a dbspace with 2 chunks. The first chunk is almost full, the second has a lot of space. What will hapen when the first one is completaly full ? Informix will show a 0 on onstad -d command for this chunk ? Enviado desde mi iPhone **************************************************************************** *** Forum Note: Use "Reply" to post a response in the discussion forum.