DB_FILE_MULTIBLOCK_READ_COUNT parameter
DB_FILE_MULTIBLOCK_READ_COUNT is one of the parameters you can use to minimize I/O during table scans. It specifies the maximum number of blocks read in one I/O operation during
RMAN-08137: WARNING archived log not deleted, needed for standby or upstream capture process
When he tried deleting archivelog manually with RMAN on primary db host, he got following warning:
“归档日志未删除, 因为备用或上游捕获进程需要它”
推荐两组linux性能分析工具
除了linux中长用的vmstat,iostat,top,sar等工具外有两组轻量的工具也值的推荐，
一个就是经典的IBM 的nmon+nmonanalyser
另一个是Collectl+Graphite
Memory Notification: Heap size nnnnK exceeds notification threshold (51200K)
Memory Notification: Library Cache Object loaded into SGA
Heap size 106084K exceeds notification threshold (51200K)
KGL object name …
know more about dbms_job fails
When job execution fails, the SNP processes attempts to rerun the job one minute later. If this run fails, another attempt is made in two minutes and another in four minutes. The job queue doubles the retry interval until it exceeds the normal execution interval..
goldengate update collisions
Total updates 12.00
Total deletes 0.00
Total discards 0.00
Total operations 13.00
Total update collisions 12.00
sqlplus autotrace sql Statistics value全部为0
0 db block gets
0 consistent gets
0 physical reads
0 redo size
0 bytes sent via SQL*Net to client
0 bytes received via SQL*Net from client
0 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
62 rows processed
ora-600 [kcbgcur_9] internal error when ALTER DATABASE ADD SUPPLEMENTAL LOG DATA
SQL> ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA
*
ERROR at line 1:
ORA-00600: internal error code, arguments: [kcbgcur_9], [8388681], [25],
[100663296], [33554432], [], [], []
How to stop or kill datapump jobs?(停止数据泵job)
3 begin
4 hdl := dbms_datapump.attach(‘SYS_IMPORT_FULL_03′,’SYSTEM’);
5 DBMS_DATAPUMP.STOP_JOB(hdl,1,0);
6 end;
迁移controlfile 从文件系统到ASM
alter system set control_files=’+DATA/ANBOB/CONTROLFILE/current.260.793738081′,’+DATA/ANBOB/CONTROLFILE/current.261.793738087′,’+DATA/ANBOB/CONTROLFILE/current.276.793737555′ scope=spfile;
计算controlfile size，dd 迁移raw device中的controlfile
Control Seq=53995=0xd2eb, File size=594=0x252
File Number=0, Blksiz=16384, File Type=1 CONTROL
Logical block number 1 (header block)
Script: 查看datafile 的HWM,估算resize 最小size
数据文件如果有2g，先create一个大表占了1G,后来建了个几M小表，再把大表drop 掉加purge选项，向把数据文件resize到100M，往往会失败，在磁盘紧张的情况下，想知道数据文件最小值是多少？就要计算datafile HWM
How to list all events?（oracle事件列表）
其中有两个编号段比较特殊
1，错误编号-10000到-10999 不是真正的错误，是保留下来用于debug使用
2，错误编号-20000到-20999是自定义异常，错误信息最大2048B
hanganalyze 分析 dbms_ijob.broken无效的问题
HANG ANALYSIS:
==============
Open chains found:
Chain 1 : :
<0/1777/32406/0x5275fca0/13913/SQL*Net message from client>
— <0/1477/37455/0x5275e4e8/16043/enq: TX - row lock contention>
ora-600 [3708] [910] internal error issue
SQL> shutdown immediate
ORA-00600: internal error code, arguments: [3708], [910], [], [], [], [], [], []
Basically this error is raised because LGWR timmed out.
ORA-00600 [keltnfy-ldmInit] internal error issue
ksedmp: internal or fatal error
ORA-00600: internal error code, arguments: [keltnfy-ldmInit], [46], [1], [], [], [], [], []
excel 列匹配公式
在Excel中有时有需求，需要像数据库一样，做两个sheet或文件的关联，把一个表中匹配Key的值更新到当前Key的某一列，不想让把excel那么多字段导入db，就可以利用伟大的excel 公式做到实现
About Columns Order(列先后顺序)
有时总是忽略在列的顺序带来的性能开销，还有列的null值字段的位置,想理解这个问题要首先程序列数据是如何在block上存储的，并且是如何定位的？
