How to check for compression in Informix® tables

How To

Summary

Query the sysmaster database for any partitions with the compression flag.

Objective

Identify which tables are compressed.

Environment

Use the DBAccess® tool to query the sysmaster database pseudo-tables.

Steps

You can use one of the following to check for compression in tables:

1) The sysmaster:syslicenseinfo has the compression flag set in the feature_flags column:

select first 1
case when sysmaster:bitval(feature_flags, "0x2000")=1 then "TRUE"
else "FALSE"
end compression
from syslicenseinfo
order by year desc, week desc

2) Query the sysmaster systabnames and sysptnhdr tables for any partitions with the compression flag:

SELECT hex(i.flags) flags, hex(i.partnum) partition, trim(n.dbsname) || ":" || trim(n.owner) || ":" || trim(n.tabname) table 
FROM sysmaster:systabnames n, sysmaster:sysptnhdr i 
WHERE (sysmaster:bitval(i.flags, "0x8000000") = 1) 
    AND i.partnum = n.partnum