Recommendation for the Real Application Cluster Interconnect and Jumbo Frames

February 9, 2012 Architect, oracle, RAC, software 2 comments

Recommendation for the Real Application Cluster Interconnect and Jumbo Frames

Applies to:

Oracle Server – Enterprise Edition – Version: 9.2.0.1 to 11.2.0.0 – Release: 9.2 to 11.2
Information in this document applies to any platform.
Oracle Server Enterprise Edition – Version: 9.2.0.1 to[……]

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11g nested loop faster than 10g

February 3, 2012 11g, oracle No comments

在pythian看到了一个测试,是否证明了oracle 11g is x% faster than 10g?(oracle官方的说法)

First, you have to create and fill a table to run your query :

create table gark
(id1 number not null,
id2 number not null,
id3 number not null);

begin
for i in 1..100000 loop
insert into gark(id1, id2, id3)[……]

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11g partition new features

February 3, 2012 11g, oracle No comments

总结了11g partition new feature
11G Introduced partition extensions:
-Interval partitioning
-REF partitioning
-More Composite Partitioning
-Virtual Column-based partitioning
-System Partitioning
-Introduced Partition Advisor.

Partition Types
Let us discuss each of the above features briefl[……]

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优化mysql ibdata*

January 18, 2012 maintain, MYSQL No comments

由于此前的mysql salve服务器没有进行规划,一些参数都是使用的默认参数,导致innodb datafile 无限制增长,所以需要重新规划一下datafile空间的分配,以及其他参数的优化

version:

mysql>
mysql>
mysql> select version()
-> ;
+————+
| version() |
+————+
| 5.5.14-log |
+————+
1 row in set (0.02 sec)

mysql>

配置sysctl limit
[roo[……]

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HugePages on Linux

January 16, 2012 linux, system 5 comments

Regular Pages and HugePages

This section aims to give a general picture about memory access in virtual memory systems and how pages are referenced.
When a single process works with a piece of memory, the pages that the process uses are reference in a local page table for the specific process. T[……]

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Scripts:show_space

January 16, 2012 maintain, oracle No comments

修改过的show_space 支持ASSM

create or replace
procedure show_space
( p_segname_1 in varchar2,
p_space in varchar2 default ‘MANUAL’,
p_type_1 in varchar2 default ‘TABLE’ ,
p_freespace in varchar2 default ‘N’,
p_owner_1 in varchar2 default user)
as
p_segname varc[……]

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How does “Nologging” attribute

January 13, 2012 Internals, oracle No comments

NOLOGGING is supported in only a subset of the locations that support LOGGING. Only the following operations support the NOLOGGING mode:
DML:
1. Direct-path INSERT (serial or parallel) resulting either from an INSERT or a
MERGE statement. NOLOGGING is not applicable to any UPDATE operations
resu[……]

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Logic standby delay when query with for update clause

January 11, 2012 oracle, replication, system No comments

今天遇到一个奇怪的问题,3个logic standby 中有一个delay 查看任何日志都没有发现错误,有一个transaction在apply一个SQL,这条SQL没有任何问题,SQL所涉及到的表也没有任何问题
当时的apply情况如下:

SID USERNAME MACHINE EVENT PARAM W WT SQL ST LT LOGON_TIME
—— ———- —[……]

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Scripts:xplan_extended_display_cursor

January 9, 2012 maintain, oracle No comments

Alter session set sql_trace=true;
Alter session set STATISTICS_LEVEL = ALL;

set echo off verify off termout off
set doc off
doc
— ———————————————————————————————-

— Script: xplan_extended_display_cursor.sql

— V[……]

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Oracle 坏块处理(final)

January 8, 2012 maintain, oracle 2 comments

收到开发人员报告,oracle出现坏块,信息如下:

Hex dump of (file 7, block 1407500) in trace file /data/oracle/admin/orcl/bdump/orcl_p004_7383.trc
Corrupt block relative dba: 0x01d57a0c (file 7, block 1407500)
Fractured block found during crash/instance recovery
Data in bad block:
type: 6 format: 2 rdba: 0x01d57a0[……]

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