Recently, I was in a situation where I had to query a Db2 database on a mainframe. I was also in a situation where the knowledge and documentation on that mainframe was not very widespread. So there I found myself, sitting in the dark with only a so-called 3270 screen looking at me, waiting for a first step that I would take.<\/p>\n
The first question: how are the tables called. Second question: what tools to use to query the database.<\/p>\n
I remembered from a distant past that IBM has a so-called “File-Aid” for Db2. This tool has a browse option that allows you to browse\u00a0interactively tables in a Db2 database. The nice thing about it that the browse mode accepts wild-cards like *. When multiple answers are possible a pop-up appears that gives a clear choice on the possiblities. I used this tools to get a hunch of the table-names and to get a first impression on the content of the tables.<\/p>\n
Once I had a list of filenames, I started with a second tool that gave me more insight. This tool is called “Spufi”. This tool basically uses two files (or datasets as they are called on a mainframe). One file is used to store the SQL statements, whereas a second dataset is used to capture the output. I realised that the two files must be allocated beforehand and that both files could best reside under your own name. I created two files: “tom.input.sql”\u00a0 and “tom.output.txt”. I then used these two names in the first screen of Spufi where the exact names of input- and output files is being asked for.<\/p>\n
This allowed me to start investigating the database.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Recently, I was in a situation where I had to query a Db2 database on a mainframe. I was also in a situation where the knowledge and documentation on that mainframe was not very widespread. So there I found myself, sitting in the dark with only a so-called 3270 screen looking at me, waiting for […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-230","post","type-post","status-publish","format-standard","hentry","category-nice-to-know"],"_links":{"self":[{"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=\/wp\/v2\/posts\/230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=230"}],"version-history":[{"count":0,"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=\/wp\/v2\/posts\/230\/revisions"}],"wp:attachment":[{"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=230"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/archief.van-maanen.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}