In my post on the differences between ADD TRANDATA and ADD SCHEMATRANDATA, I highlighted the differences between the two ways of adding supplemental logging to tables. One of the things I pointed out was that ADD SCHEMATRANDATA doesn’t add any supplemental log groups (SLG). Without SLGs then how does ADD SCHEMATRANDATA work? That was the question I was left with. So I started digging around to find the answer and I think you may be (more...)
Since I published posts on how to retrieve command history within GGSCI using the Oracle provided commands of “history” and “fc”, I was pinged a couple of times by some friends asking about “rlwrap” usage with GoldenGate. The answer is a simple yes, rlwrap can be used with Oracle GoldenGate.
What exactly is “rlwrap”?
Ever get tired of typing the same command over and over again in Oracle GoldenGate GGSCI? Well, Oracle has provided a history recall function into GGSCI, I talked about his in an earlier post. This post on history recall can be found here.
In this post, lets take the command recall and how these commands can be edited. In Oracle GoldenGate 12c, Oracle has provided an GGSCI command called “FC”. The “FC” command is used (more...)
If you are familiar with using Oracle GoldenGate, you know that on the source side of the equation you have to enable supplemental logging and sometimes force logging on the database. I traditionally do both just to make sure that I capture as much as I can into the redo stream from the transactions on the database. For Oracle GoldenGate purposes, this is not the only thing you need to turn on to ensure all (more...)
Use of ANSI SQL is a personal thing.
Historically I have not been a fan apart from where it makes things easier/possible.
This reticence was mainly due to optimizer bugs and limitations in the earlier days.
Recently I have been using it much more because I find that the developers I interact with prefer it / understand it better.
You might/should be aware that Oracle will rewrite ANSI SQL to an Oracle syntax representation, this (more...)
I have 12c setup on OEL 6.7 on my VM and while trying to access EM express, I was receiving the error
Just for the notes, a user can log into EM Express using URL
and port details can be found using
lsnrctl status | grep HTTP or select dbms_xdb_config.getHttpsPort() from dual;
Clicking on the “Get Flash” takes you to abode flash page from where you can download the rpm for flash.
While playing around 188.8.131.52 db, I ran my usual script to check tablespace usage details and it took ~59 secs (Elapsed: 00:00:59.02), which was high.
Ran the sql using “gather_plan_statistics” hint and below lines in the execution plan were of interest –
| 34 | HASH GROUP BY | | 1 | 6 | 3 |00:00:58.68 | 129K| 54801 | 1160K| 1160K| 758K (0)| | 35 | VIEW | DBA_FREE_SPACE (more...)
Why you might want to think twice about using INSERT ALL.
One of those things I knew and then forgot.
So, let’s say you’ve got three tables or a partitioned table or something like that.
Let’s use regional tables for simplicity.
drop table t1_r1; drop table t1_r2; drop table t1_r3; create table t1_r1 (col1 varchar2(2) not null ,col2 number not null ,check( col1 in ('R1'))); create table t1_r2 (col1 varchar2(2) not null ,col2 number not (more...)
This blog post is more of a note for myself on configuring ASMLib.
ASMLib is an optional utility that can be used on Linux systems to manage Oracle ASM devices.
ASMLib consists of the following components:
An open source (GPL) kernel module package: kmod-oracleasm
An open source (GPL) utilities package: oracleasm-support
A closed source (proprietary) library package: oracleasmlib
On my Oracle VMBox, I performed the below steps –
1. Check the installed packages related to (more...)
To build Oracle Clusterware Database at Home, I believe , RAC ATTACK is the best place to learn. Its is a free curriculum and platform for hands-on learning labs related to Oracle RAC. While reviewing the article, I thought to perform 12cR1 RAC installation on OEL 7.2.
Attached is the document :- 12c_RAC_on_OEL7
The attached article is inspired by
Deploying Oracle RAC (more...)
As I sit here working on performing some GoldenGate migrations to AWS for a client, I’ve been thinking about the glimpse of GoldenGate Cloud Service (GGCS) that was provided to me earlier this week. That glimpse has helped me define what and how GGCS is going to work within the Oracle Cloud space. Ever since this service was announced back at Oracle Open World 2015, I’ve been wanting to get my hands on this cloud (more...)
For most of our database set-ups we use a different TEMP space for application users than for end-user/support/developer/reporting usage.
The intention is to minimise the potential impact of a rogue ad-hoc query on the main applicaiton.
However, turns out this is ineffective IF you use:
ALTER SESSION SET CURRENT_SCHEMA = main_app_schema;
This is documented but I wasn’t previously aware.
No surprise that this learning opportunity was presented as a direct result of a rogue query (more...)
In my earlier post I discussed what Dead Connection Detection is and why you should use it – read more here Oracle TNS-12535 and Dead Connection Detection
The pre-12c implementation of DCD used TNS packages to “ping” the client and relied on the underlying TCP stack which sometimes may take longer. Now in 12c this has changed and DCD probes are implemented by TCP Stack. The DCD probes will now use the TCP KEEPALIVE socket (more...)