I don't think there is anything specificly about a timestamp index vs
another index that is bad. All indexes will have an extra overhead
at insert/delete/update time as they are implemented as a separate file
maintaining an btree index on disk. For your application it would
depend if the benefit to queries that use the timestamp collumn out
weigh the overhead of maintaining the index.
Providing performance advice is hard. About the only generic thing
i can say about insert performance is to do as many inserts as possible
in a single transaction so as to avoid I/O bound performance on the
synchronous write of the commit record. Also use and reuse prepared
statements as possible.
There are a lot of successful derby applications doing large numbers of
inserts from evidence of past postings on derby user and derby developer
list. To get more help I suggest you post more details to the list
for those users to help. Best would be to include a reproducible test
case of the problem area, including source code. That makes it the most
likely you can get useful feedback. Also including some basic
performance goals would be good - ie. hoping to get N inserts of rows
with the following DDL in M seconds made by P concurrent threads on
X hardware with Y disk technology.
On 1/8/2015 11:34 PM, kosurusekhar wrote:
Hi Folks,
We have three tables where will have lot insertions per minute. In all three
tables we have TIMESTAMP columns, And we kept index for these timestamp
columns. This timestamp values always system time when the row is inserted.
My doubt is whether maintaining the index tree for this kind of data
(timestamp) will be overhead for derby database. Because Timestamp contains
including seconds also right, I feel personally to create index structure &
maintaining this structure could be little overhead for derby server.
Please correct me if I am wrong. In this scenario how to improve performance
while huge insertions happening into these tables.
Thanks in Advance.
Regards
Sekhar.
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