If you want help in understanding how to use the context option (currently called Oracle Text) the appropriate forum is at https://forums.oracle.com/forums/forum.jspa?forumID=71

Thanks. I already have set the memory to the max allowed (2GB) and the default to 1GB. The tablespaces were created with “defaults” which happen to have pctincrease 50%. I am moving to the auto-allocate as I get the chance to do so. We also have partitioned tables (to mainly help with the deletes) and we use tablespaces in a round-robin (tablespace for the day essentially) in case a datafile gets corrupted ad the whole tablespace becomes unavailable until the data files are resolved.

Anyway, how to find out if the memory allocations/parameters are working optimally?

Unless you’re on a very old version of Oracle you shouldn’t be thinking about things like initial, next and pctincrease anyway.

As a general guideline for tablespaces (and block sizes) – if you can’t think of a good reason for changing the defaults then use the defaults.

In the case of context it’s probably more important to worry about setting the memory allocation attribute for creating the context index as this dictates the volume of data (e.g. number of files) that the code will read as a unit when creating the index – and the size of the LOB content of the index tables will be dictated by the volume of data read as a unit.

What are the implications of specifying the Storage preference for the $I, $N, etc tables?

v_Attributes := ‘TABLESPACE storage(initial 1K next 1K pctincrease 0);
CTX_DDL.Set_Attribute(,I_TABLE_CLAUSE,);

OR is it just better to specify just the tablesapace and take the defaults.

Regards

Sorry about the delay in replying – sometimes I just lose track of comments because of all the travel I do. I’ll be writing up a short note in the next few days to answer this question.

if you can please put some highlight some options or point out some way using which one can decide which option for LOB storage (CACHE, CACHE READ, or NOCACHE; LOGGING or NOLOGGING) should be used.

In our system we are having tables with CLOB columns, the system is third party and mostly deletes on the tables with CLOB column is taking a lot of time. I was wondering if changing some storage settings will help us, presently we have ENABLE STORAGE IN ROW CHUNK 8192, NOCACHE LOGGING.

Regards,
Vijay.

How you decided RETENTION vs PCTVERSION ?

Thank you and regards,
Igor

Satish, the minimum size for an ‘out of line’ LOB is one “chunk”, and the minimum size of a chunk is one block. Most of our LOBs were smaller than 8KB, but the tablespace for the LOB segment was 16KB – so most of our LOBs were using less than half a block. By halving the block size we saved half the space – the half that we were wasting in most blocks.

How much was ‘recycle pool’ size after caching? I wonder how much buffer cache is required to CACHE 0.25 TB of LOB.

Thanks