So this customer has an Exadata quarter rack and they have an IB listener configured on both DB nodes (for DB connections from a multi-racked Exalogic system). We were adding a new DB node to this rack. So just followed the standard procedure of creating users, directories etc on the new node, setting up ssh equivalence and running addNode.sh. All went fine but root.sh failed. Little looking into the logs revealed that it (more...)
A script hacked together a couple of years ago from a clone of a script I’d been using for checking space usage in the older types of segments. Oracle Corp. eventually put together a routine to peer inside securefile LOBs:
rem rem Script: dbms_space_use_sf.sql rem Author: Jonathan Lewis rem Dated: Dec 2013 rem Purpose: rem rem Last tested rem 220.127.116.11 rem 18.104.22.168 rem Not tested rem 11.1. (more...)
Databases or schemas tend to get moved around between different servers or even datacenters for hardware upgrades, consolidations or other migrations. And while the work that needs to be done is pretty straight forward for DBAs, I find the most annoying aspect of that is updating all client connect strings and tns entries used with new IP addresses and – if not using services – also the SID as the instance name might have changed.
One of the nice things about declaring your (basicfile) LOBs as “enable storage in row” is that the block addresses of the first 12 chunks will be listed in the row and won’t use the LOB index, so if your LOBs are larger than 3960 bytes but otherwise rather small the LOB index will hold only the timestamp entries for deleted LOBs. This makes it just a little easier to pick out the information you (more...)
At the end of the last installment we had seen a test case that caused Oracle to add a couple of redundant new extents to a LOB segment after one process deleted 3,000 LOBs and another four concurrent processes inserted 750 LOBs each a few minutes later (after the undo retention period had elapsed). To add confusion the LOBINDEX seemed to show that all the “reusable” chunks had been removed from the index which suggests (more...)
Here’s a simple script that I’ve used for many years to check space usage inside segments. The comment about freelist groups may be out of date – I’ve not had to worry about that for a very long time. There is a separate script for securefile lobs.
rem rem Script: dbms_space_use.sql rem Author: Jonathan Lewis rem Dated: Nov 2002 rem Purpose: rem rem Last tested rem 22.214.171.124 rem 11.2. (more...)
There are many posts about the amount of memory that is taken by the Oracle database executables and the database SGA and PGA. The reason for adding yet another one on this topic is a question I recently gotten, and the complexities which surrounds memory usage on modern systems. The intention for this blogpost is to show a tiny bit about page sharing of linux for private pages, then move on to shared pages, and (more...)
With the introduction of CDB, many views have added column CON_ID.
DB1:(SYS@DB1):PRIMARY> select inst_id inst,sid,serial#,program,machine from gv$session where sid in ((select * from dba_blockers)); select inst_id inst,sid,serial#,program,machine from gv$session where sid in ((select * from dba_blockers)) * ERROR at line 1: ORA-00913: too many values DB1:(SYS@DB1):PRIMARY> desc dba_blockers; Name Null? Type ----------------------------------------------------- -------- ------------------------------------ HOLDING_SESSION NUMBER CON_ID NUMBER DB1:(SYS@DB1):PRIMARY> select inst_id inst,sid,serial#,program,machine from gv$session where sid in ((select HOLDING_SESSION from dba_blockers)); INST SID SERIAL# PROGRAM (more...)
With me traveling to Redwood City next week to visit HQ and then Oracle Open World the week after, I’m busy during many of my off hours preparing a new Raspberry Pi STEAM setup for a maker’s faire the beginning of October.
I’d heard that many were having challenges with installing different HATs on their new RPI 3, especially older ones like the Pibrella.
This is still one (more...)
I had a scenario today where I was loading a table and a particular column is known by multiple names in different source systems and thus to different people. In order to make everyone happy on this occasion, I wondered if I could create a normal column for one of the multiple names and then use virtual columns pointing at the normal column, for the other names.
I’m aware there are several ways of skinning (more...)
So if you are filling an OEDA for Exadata deployment there are few things you should take care of. Most of the screens are self explanatory but there are some bits where one should focus little more. I am running the Aug version of it and the screenshots below are from that version.
- On the Define customer networks screen, the client network is the actual network where your data is going to flow. So typically (more...)
His review is on the following link. Thanks Rob.
I was googling for things related to NOLOGGING operations and found this useful post on the Ask Tom web site: url
There is a nice table in the post that shows when insert operations generate redo log activity. But it isn’t formatted very well so I thought I would format the table here so it lines up better.
Table Mode Insert Mode ArchiveLog mode result ----------- ------------- ----------------- ----------- LOGGING APPEND ARCHIVE LOG redo generated (more...)
I am glad and super excited to present and attend the conference. I am going to present the following two sessions:
- Exadata Migration Recipes - Secret Sauce for a Tasty Migration
'Why is it,' he said quietly, 'that quite often even the things which are correct just don't seem to be right?' -- Norton Juster, The Phantom Tollbooth
For some time now Oracle has used bloom filters to speed the processing of select statements; unfortunately in 126.96.36.199 converting a select statement that uses a bloom filter into an ‘insert into … select’ form causes Oracle to abandon the bloom filter altogether. Let’s (more...)