121 reputation
12
bio website twitter.com/jajathilo
location Shanghai, China
age
visits member for 2 years, 9 months
seen 2 days ago

Jun
23
comment General tuning in PostgreSQL
You need more "details". Start by getting a slow query log.
Sep
20
answered What is difference between primary index, secondary index, unique index and normal index?
Jun
4
comment Convert Oracle database to Derby
Do you use any "interesting" features of Oracle? (Stored procedures, functional indexes, BLOB etc)
May
22
awarded  Nice Answer
May
22
awarded  Yearling
Jul
6
comment Why does my ORDER BY sort two tables before the EXCEPT (slow) and not after (fast)?
It does not sort before the hashmatch, it sorts and then does a merge-join (not a hash-join). Maybe there is a hint to force a hash-join (or prevent a merge-join)?
Mar
2
comment Does the number of indexes effect the modification of table?
How does an unnecessary index negatively effect read performance for a key lookup or a RID lookup? That index is not going to be touched at all, right?
Feb
25
awarded  Teacher
Feb
25
comment Does the number of indexes effect the modification of table?
"If you remove the unwanted indexes, it will improve the read/write performance on your table": How does an unnecessary index affect read performance?
Feb
24
answered Does the number of indexes effect the modification of table?