Indexing only specific rows, IT WORKS NOT – fixed (works)

So, last year I was in Belgrade on asktoms seminar (Belgrade Seminar 2014.zip on asktom.oracle.com), now I have time to play, so I wanted to test indexing only specific rows, I decided 1. As you will see you can index specific values, but some additional “objects” are necessary to let it work. SQL> create table…

RAC 11g installation demystified

Hi, my colleague Marek found a link which explains how to install a RAC. As I know only partially some concepts, it will be helpful for me and also for you if you want to know more about RAC. Link: Oracle RAC with GNS

How to create a 12c Container DB manually

Hi, as the world is going always forward, I cannot wait until my customer decides to use the new 12c technology, virtualization rocks, so my virtualbox rocks too. I know it costs money if you use it in production so it’s as always, the money rules the world. I have googled a lot to find…

TM contention and INSERT /*+ APPEND */ parallel sessions?

Today I did a reorganization on 1,7TB tablespace, finally reduced to 620GB. (I have to have 10% free in a tablespace to not cause alerts). There were some tables arround 30GB with smaller LOBs and two tables with one 1TB LOB and 500GB LOB. To know it will work a testcase on the standby database…

Little Statspack Performance monitoring SQL

Well, you know Average Active Sessions, if you don’t have AWR than this is a way how to get some information, use Statspack. The query displays how many users were working(active) in a second. select t.snap_time,round(t.dbtime/t.elapsed,2) as “AvgActiveSessions” from ( select snap_time, stat_name, nvl(round((l.value-lag(l.value) over (order by l.snap_id))/1000000,2),0) as dbtime, nvl((s.snap_time-lag(s.snap_time) over (order by s.snap_id asc))*24*60*60,0)…

Gather stats on tables with data

Sometimes during support of upgrades of apps we have some tasks to gather statistics on tables. I have tried to implement a procedure which is gathering it. The input is the schema name. As I cannot implement procedures just because it makes things easier I have implemented it on a test database and tested it…

Monitoring redo generation

Sometimes I am checking how much redo is generated during the day to know if I have enough space in the arch destination during reorgs. To check redolog generation I use: break on SUBSTRING skip 1 compute sum label ‘TOTAL’ of MB on SUBSTRING set lines 180 pages 999 select count(1) “Rate” ,trunc(FIRST_TIME,’HH24′) “By Hour”,round(sum(blocks*block_size)/1024/1024,2)…