Hi.



I have developed my first application with VB.NET at work (junior
developer) and basically it reads several thousands of lines from X number
of files, and inserts them into a mysql database.



The application consists of several steps:

1) Dump all lines with all fields into a temp table.

a. This works fine. Optimal speed for the hardware we have.

2) Query temp table to obtain certain. I query by a unique ID. I
insert all unique ID (isn field). If the ID matches my interests, I insert
it into an ArrayList.

a. Query: SELECT COUNT(SUBSTR(ISN,2)), SUBSTR(isn, 2) FROM
SMS.TEMPDATADUMP WHERE error = 0 GROUP BY SUBSTR(ISN,2) HAVING
COUNT(SUBSTR(ISN,2)) = 4

b. The isn is not unique per line, but per data (sms)

c. Once I have all isn on an arraylist, I do the following query:

i. SELECT
select, my, fields,of,interest FROM SMS.TEMPDATADUMP WHERE SUBSTR(ISN, 2)
= '" & isn & "' ORDER BY type LIMIT 1

d. To obtain some data. During the process I query around 10 times
other table per ISN.

e. Here is the problem. If I have a few files to process (around
3000-4000 lines in total, small array) this steps work fine, good speed.
But If I have big files or a lot of files (more than 10000 lines in total,
big array), this steps are incredibly slow. Queries and inserts are too
slow. Meaning, one-two inserts per second, while the other case inserts are
around 800 per second.



Our hardware is not optimized for database server, but I don?t have other
choice. It is mostly a desktop computer

Intel core i5, windows 32 bits, 3GB RAM, one disk 500GB 7200rpm.



I have tried some optimizations commented in mysqlperformance blog without
success.

Any way to optimize this?



Thank you very much in advance.





Adri?n Espinosa Moreno.