Which Column has Changed in Every Row? Mustafa, 2020-11-022020-11-03 Hi, Edit: Thanks to Chris Saxon who is from asktom team, checked my code and warned me about a problem. Not to overload the PGA fetch_rows function only fetches 1024 rows at once so every row set chunk size is 1024. In this case for the 1025th row, previous row… Continue Reading
Direct Path Insert &/vs Conventional Insert Mustafa, 2020-10-27 Hi there, I couldn’t write anything for a while. Those days were busy. So I would talk to about direct path insert and conventional insert. Many people think that they are using “direct path insert” when used sqlldr utility but they are not. it is easy to confused batch insert… Continue Reading
Flashback Data Archive Problems! Mustafa, 2020-09-102020-09-10 Hi, if you don’t know about flashback data archive you can check this post first: https://mustafakalayci.me/2019/03/02/goodbye-log-triggers-welcome-flashback-data-archive/ I mentioned about flashback data archive (FDA) in that post and really flattered it. Well, maybe I shouldn’t! FDA is really fast dml tracking method but thanks to Peter Schlaeger, I noticed some potential… Continue Reading
Oracle Table Compression Part1 Mustafa, 2020-09-10 Hi, I have been dealing with table compression a lot during my development period and I still do. I wanted to share some information about table information but I believe this will be a long explanation so I will write them in parts and this is part1. Table compression is… Continue Reading
Redo Log Switch Order Mustafa, 2020-09-032020-09-04 Hi, I always have the impression that redo log switch occurs in group number order but a small test showed me, I was wrong. As you know redo log is one of the most important part of a Oracle database. it almost protect everything! your data in memory, data file,… Continue Reading
NVME Drives and Oracle Database Mustafa, 2020-08-202020-08-21 Hi There, NVME drives are so hot these days. They have amazing read/write speed. my old samsung ssd drive can read and write around 550/530 MB per second and my even older 2.5inch hdd drive has 45/20 MB per second. Current NVME disc drives has around 3500 read and 3000… Continue Reading
Control File Content and the Limits Mustafa, 2020-08-11 Hi, I would like to talk about Control File (CF). One of the most important component of the Oracle Database. It stores many critical data and limits for the database. Last SCN (System Change Number). Last Checkpoint Information. Data file locations. Redo log file locations. RMAN Repository (where the backup… Continue Reading
Frequent and Fast Refresh Materialized Views has a Big Problem! Mustafa, 2020-07-252020-07-25 Hi, While I was checking V$SQL_PLAN view for a whole different reason, I realized that some of the cursors has incredibly high child cursors. I started to dig and finally I find the problem. My customer have a few frequently fast refreshed materialized views. One of them is refreshed every… Continue Reading
Is It Possible to Change SQL Statement in the Database? Mustafa, 2020-07-042020-07-04 YES! Hi, today I want to write about something which has been asked for many times to me. Let’s say you have an application and it is running very poorly designed sql statements in your database and you are really bored having fights with development teams to ask a change… Continue Reading