Hi,
I have noticed that when I execute the query in 9i, I/O Phys Read in
Sessions screen (OEM) is showing a value of 4500 for each execution of the
query.
Whereas in 8i it is only 5.
same case with logical reads.
System Params
shared_pool_reserved_size 55364812
shared_pool_size 528482304
db_block_buffers 0
db_block_checking FALSE
db_block_checksum TRUE
db_block_size 8192
db_cache_advice ON
db_cache_size 142606336
db_file_multiblock_read_count 16
sga_max_size 1309747452
Can you help.
Regards,
Shahed Baig . M
"kazi " <oracledba-ezmlmshield-x74885030.[Email address protected]
25/01/2005 10:53
To: "LazyDBA Discussion" <[Email address protected]
cc:
Subject: Re: Query issue in 9i
You should provide more data. But first you should gather statistics.
Older way:
analyze table AAA compute statistics;
will do, but it is better to use dbms_statistics. If your problem persist,
then serious approach to optimizing should be taken. Consider:
- indexes,
- size of table
- distribution of values in critical columns (histograms)
- your query
- whole execution plan data
...
KAzi
Shahed wrote:
>Hi gurus,
>
>I have migrated from 8i to 9i. There is a query which was quite faster in
>8i (1sec) but it became slow in 9i (1 min).
>I ran the explain plan. The position value is as follows
>in 8i Cost =1846
>in 9i Cost = 93241102
>
>pls suggest how to fix this issue
>
>Both have optimizzer_mode set to "choose".
>
>Regards,
>Shahed Baig . M
>
>
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