Mayuresh Nirhali wrote:
Hello,
I was looking at Derby-606 and was able to reproduce the bug.
I am working with a table of 30 million rows of the schema mentioned
in the JIRA entry.
I have a query regarding the size of the table before and after
INPLACE_COMPRESS_TABLE command.
After creating the table and inserting the 30 million records, a simple
'du -sk' shows the size as,
12008738 testdb
I exeucted INPLACE_COMPRESS_TABLE through ij and the size returned
from the same command is,
12020239 testdb
Since, I have not performed any deletes, the reduction in the size is
not expected. ofcourse, the testdb directory does not include derby.log.
so, I am wondering about the little increase in the size. Is it in the
form of some other logs ? Can someone throw some light on this
increase in size ??
I would also appreciate any additional information on
INPLACE_COMPRESS_TABLE.
TIA
Mayuresh,
Hi -
I'm going to make a guess that the increase is because in the initial
dataload some of the free space reserved in each page (probably index
pages) was utilized as new records were added and that the compress
restored the default free space percentage for those pages thus
spreading the records out over more pages. You can check my speculation
by comparing the before and after sizes of the files for each table and
index in the seg0 directory to see which are growing. Be sure to check
that the number of before and after files are the same (that there are
no d*.dat files waiting to be removed or log*.dat files that contain
transaction information that need to be processed.).
HTH
