# ISN limit in ADABAS file reached **URL:** \ **Category:** Forum\ **Tags:** Adabas-Natural, Adabas, Adabas-on-Mainframes, Adabas-Basics-on-Mainframes\ **Created:** [May 16, 2006, 9:22pm UTC](https://techcommunity.softwareag.com/t/isn-limit-in-adabas-file-reached/58017 "2006-05-16T21:22:40Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Ralf\_Geritz](https://avatars.discourse-cdn.com/v4/letter/r/c4cdca/32.png) [@Ralf\_Geritz](https://techcommunity.softwareag.com/u/Ralf_Geritz)\ **Post date:** [May 16, 2006, 9:22pm UTC](https://techcommunity.softwareag.com/t/isn-limit-in-adabas-file-reached/58017/1 "2006-05-16T21:22:40Z")
Hi all, one of my ADABAS files is approaching the 16,7 mio. limit due to the three bytes length of each ISN. My idea is to increase the ISN up to 4 bytes. Does the following approach work: - Unload the file: – ADAORD REF FILE=nnn,ISNSIZE=3 - Load again: – ADAORD STORE FILE=nnn,ISNSIZE=4,MAXISN=20000000,OVERWRITE Are there any side-effects I have to consider, maybe during utility execution or later during access to that file. Any ideas are welcome since this is the first time I have to perform this 😉 Thanks in advance for answers, Ralf ---
**Author:** ![Svend\_Erik\_Nielsen](https://avatars.discourse-cdn.com/v4/letter/s/e19adc/32.png) [@Svend\_Erik\_Nielsen](https://techcommunity.softwareag.com/u/Svend_Erik_Nielsen)\ **Post date:** [May 22, 2006, 1:56pm UTC](https://techcommunity.softwareag.com/t/isn-limit-in-adabas-file-reached/58017/2 "2006-05-22T13:56:14Z")
Hi Ralf. This is probably more simple than you think. I have used this for ADABAS Z/os several times. ADAORD REORFASSO FILE=xxx ADAORD ISNSIZE=4 I have not seen messureable side effects. ---
**Author:** ![system](https://global.discourse-cdn.com/techcommunity/original/3X/c/d/cd19967bb605d28a72d77eb83a1cae22f3df2eb8.svg) [@system](https://techcommunity.softwareag.com/u/system)\ **Post date:** [April 2, 2021, 2:39pm UTC](https://techcommunity.softwareag.com/t/isn-limit-in-adabas-file-reached/58017/3 "2021-04-02T14:39:00Z")