# Have trouble compressing string columns **URL:** \ **Category:** Community Support\ **Tags:** kdb-and-q\ **Created:** [August 24, 2011, 6:49pm UTC](https://forum.kx.com/t/have-trouble-compressing-string-columns/7265 "2011-08-24T18:49:00Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Jay3](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jay3](https://forum.kx.com/u/Jay3)\ **Post date:** [August 24, 2011, 6:49pm UTC](https://forum.kx.com/t/have-trouble-compressing-string-columns/7265/1 "2011-08-24T18:49:00Z")
Hi, everybody, I am new to kdb+ and I have a newbie question.I tried compression in kdb2.7, it works very well. But when I triedto compress tables with string columns(instead of symbol), it failed.It doesnt not pass the validation. Anybody know how to do this?Thanks a lot. ---
**Author:** ![charlie1](https://avatars.discourse-cdn.com/v4/letter/c/ec9cab/32.png) [@charlie1](https://forum.kx.com/u/charlie1)\ **Post date:** [August 25, 2011, 10:48am UTC](https://forum.kx.com/t/have-trouble-compressing-string-columns/7265/2 "2011-08-25T10:48:00Z")
this should be fine. e.g. q)`:t/ set([]string 10000?`8) `:t/ q)-19!(`:t/x;`:z/x;17;2;9) 84.96801 q)-19!(`$":t/x#";`$“:z/x#”;17;2;9) 42.30125 q)\cp t/.d z/.d q)get[`:t]~get`:z / matches ok 1b q)\ls -al t “… 10 Aug 25 10:45 .d” “… 80016 Aug 25 10:45 x” “… 80000 Aug 25 10:45 x#” q)\ls -al z “… 10 Aug 25 10:46 .d” “… 12028 Aug 25 10:45 x” “… 46159 Aug 25 10:45 x#” Please can you provide an example where it fails? thanks ---
**Author:** ![Jay3](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jay3](https://forum.kx.com/u/Jay3)\ **Post date:** [August 25, 2011, 4:23pm UTC](https://forum.kx.com/t/have-trouble-compressing-string-columns/7265/3 "2011-08-25T16:23:00Z")
Thank you for your response. And sorry that I didnt state my issueclearly.I am using cutil.q to compress tables partitioned by date.Here is a simple example.t:( sym:10000?`a`b`c;str:string 10000?`8);.Q.dpft[`:/home/jay/kdb;2011.08.19;`sym;`t];d: `:/home/jay/kdbdt:`:/home/jay/tmp\l cutil.qcmv cvalidate cwrite cusegz1 cinfo[d;dt;2011.08.19;`t]I got an error message:'/home/jay/tmp/2011.08.19/t/str#: No such file or directoryThanks.JayOn Aug 25, 5:48?am, Charles Skelton \ wrote:\> this should be fine.\> e.g.\>\> q)`:t/ set([]string 10000?`8)\> `:t/> q)-19!(`:t/x;`:z/x;17;2;9)> 84.96801> q)-19!(`$“:t/x#”;`$":z/x#";17;2;9)> 42.30125> q)\cp t/.d z/.d> q)get[`:t]~get`:z / matches ok\> 1b\>\> q)\ls -al t\> “… 10 Aug 25 10:45 .d”\> “… 80016 Aug 25 10:45 x”\> “… 80000 Aug 25 10:45 x#”\>\> q)\ls -al z\> “… 10 Aug 25 10:46 .d”\> “… 12028 Aug 25 10:45 x”\> “… 46159 Aug 25 10:45 x#”\>\> Please can you provide an example where it fails?\>\> thanks\>\>\>\>\>\>\>\> On Wed, Aug 24, 2011 at 6:49 PM, Jay \ wrote:\> \> Hi, everybody, I am new to kdb+ and I have a newbie question.\> \> I tried compression in kdb2.7, it works very well. But when I tried\> \> to compress tables with string columns(instead of symbol), it failed.\> \> It doesnt not pass the validation. Anybody know how to do this?\> \> Thanks a lot.\\ ---
**Author:** ![simon11](https://avatars.discourse-cdn.com/v4/letter/s/7c8e57/32.png) [@simon11](https://forum.kx.com/u/simon11)\ **Post date:** [August 25, 2011, 4:49pm UTC](https://forum.kx.com/t/have-trouble-compressing-string-columns/7265/4 "2011-08-25T16:49:00Z")
that’s an error in cutil.q - if you compress \ it should look for (and maybe compress) \ I’ll fix it you can make your compressed partition work for now by just copying over the required ..# files  sorry about that  /Simon ---
**Author:** ![Jay3](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jay3](https://forum.kx.com/u/Jay3)\ **Post date:** [August 25, 2011, 5:11pm UTC](https://forum.kx.com/t/have-trouble-compressing-string-columns/7265/5 "2011-08-25T17:11:00Z")
Thank you very much for the quick response. It solves my problem.I am looking forward to the fix.Thanks.JayOn Aug 25, 11:49?am, Simon Garland \ wrote:\> that’s an error in cutil.q - if you compress it should look for (and\> maybe compress) \>\> I’ll fix it\> you can make your compressed partition work for now by just copying over the\> required ..# files\>\> sorry about that\>\> /Simon\>\>\>\>\>\>\>\> On Thu, Aug 25, 2011 at 16:23, Jay \ wrote:\> \> Thank you for your response. And sorry that I didnt state my issue\> \> clearly.\> \> I am using cutil.q to compress tables partitioned by date.\> \> Here is a simple example.\>\> \> t:( sym:10000?`a`b`c;str:string 10000?`8);\> \> .Q.dpft[`:/home/jay/kdb;2011.08.19;`sym;`t];>> > d: `:/home/jay/kdb\> \> dt:`:/home/jay/tmp> > \l cutil.q> > cmv cvalidate cwrite cusegz1 cinfo[d;dt;2011.08.19;`t]\>\> \> I got an error message:\> \> '/home/jay/tmp/2011.08.19/t/str#: No such file or directory\\