ANBOB™

当你在windows NTFS文件系统操作大的数据文件时，有时会遇到下面的错误:
The operating system returned error 665 (The requested operation could not be completed due to a file system limitation)

# crsctl start has
CRS-4124: Oracle High Availability Services startup failed.
CRS-4000: Command Start failed, or completed with errors.

Prior to 10g you can use a unix debugger like gdb, adb or dbx to attach to a shadow process and dump the system state using the function ksudss which is the subroutine in the Oracle source code which does the same.

If you need to recovery the dead transaction record of more than 100(_cleanup_rollback_entries parameter value), PMON only responsible for cleaning up dead session, which is responsible for the SMON recovery dead transaction.

结束意味着新开始，结束会有莫名的伤感和失落，2013 有快乐有忧伤，有收获有遗憾，放下那些本该不属于你的东西， 不要急着上头条成为万人瞩目， 因为这一年你没有汪峰忙…

Shrink operations can be performed only on segments in locally managed tablespaces with automatic segment space management (ASSM). Within an ASSM tablespace. Restrictions on the shrink_clause.The shrink_clause is subject to the following restrictions…

insert into table “with” subquery Failing with the following internel error.
ORA-600: internal error code, arguments: [voprvl1], [], [], [], [], [], [], []

A description for this ORA-600 [2003] error is not yet published. ora-600 2663/2662 is a data block SCN is ahead of the current SCN.

Dynamic server tracing allows for tracing at a per-process level and can be enabled ad hoc on any running server process. This is useful for tracing individual server side processes of a specific client connection or for tracing background server processes.

上周也就是2013年的最后一天，突然客户反应有些WEB应用页面报错只提到了ora-28002, 我立即用sqlplus 登录提示是ora-28001,显然密码已经过期, 我清清楚记的才因为一起类似问题, 前不久把所有的oracle 数据库应用用户profile PASSWORD_LIFE_TIME改为unlimited，怎么还会这样呢?

Large objects (LOBs) are not supported in comparison conditions. However, you can use PL/SQL programs for comparisons on CLOB data.

skgpspawn failed:category = 27143, depinfo = 24, op = pipe, loc = skgpspawn2
…

oracle 12c release 1版本引入新功能可隐藏列(invisible columns),这个特性有很多的争议，不明白为什么ORACLE会推出这个特性，因为这个特性可能会带来很多麻烦..

今天开发的同事找我说是一个报表系统的SQL执行第一次很快，再执行就慢的几乎查询无响应，找他要来了SQL，也是常见的表关连LIFT JOIN 、GROUP BY的统计报表, 出于篇幅原因不再贴SQL， 把SQL放到TOAD 中问题依然可以再现，..

Adaptive Log File sync was introduced in 11.2. the feat […]

Sometimes we need to enable sql*net trace to diagnose sqlplus connection problems such as ora-125*
Below are the steps to configure Sql*Net verbose Client side tracing:

Each time your program performs a function call, information about the call is generated. That information includes the location of the call in your program, the arguments of the call, and the local variables ..

This script displays the top 50 longest idle times and list distribution of sessions on the instance..

高parse calls表示这些SQL不可以re-used 并且每次执行都要重新解析，理想的最佳状态是一次解析多次执行，你也知道频繁的解析会给library cache带来沉重的负担， 一个sql的执行必须先parse，解析过程包含sql 加载到shared pool, 语法检查…

When multiple connection created will insert a lot of rows in aud$ table, there may be contention in the segment header for the table. This contention can manifest itself as a buffer busy wait or a freelist wait.