map tables

cass cheng

map tables

Hi can any body say me about the map tables in OLR. I m trying to implement one OLR for one of our large ts and it seems the document says the map table is needed and it shoud be in SEGMENTED tablespaces. My question is why the MAP table need segmented tablespace.  What is the advantage if we go for SEGEMENTED for MAP tables rather than SIMPLE TABLE SPACE.

Cass

Not SARS affected DBA thoug China is more prone to SARS

 

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Jim Ruddy

Re: map tables
(in response to cass cheng)
Well, among other reasons, if you don't use a segmented tablespace REORG
will give you an error message and won't run.

Segmented tablespaces are almost always more efficient than simple
tablespaces. In the case of Online REORG, nothing is actually stored in the
data, just the index is used. Multiple mapping tables are allowed in a
single tablespace and no lock contention occurs. That would not be possible
with simple.

Jim Ruddy
DB2 for z/OS Development

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