在oracle 12.2的优化器，相比12.1已经有一些细微的变化，当我们将数据库从12.1升级到12.2，或者从12.1之前的版本，升级到12.2.需要在优化器的一些参数上引起注意，因为这些参数已经发生了变化。 在12.1中，有个统领全局的，是否启用自适应优化器参数，optimizer_adapt […]
Oracle listener日志的解析利器
我们在处理数据库的问题的时候，有时在数据库端看不到异常的等待，但是应用却报连接异常。 这种情况，有可能是在压力还没有传递到数据库，在网络这层已经发生问题了。如连接风暴，此时的数据库listener的进程已经忙不过来，将连接丢弃。（在主机层面可以看到tcpListeneDrop增加）。 我们如果去看普 […]
mongdb学习笔记
学习数据库的最好方法，是从官方文档开始看起。mongodb的官方文档在这里，但是也有中文翻译的版本，可见这里(中文翻译貌似还没完全翻译完，还有不少段落是英文的。)。 mongodb目前最新的版本是3.4版本。注：3.4版本不在支持x86 32位的系统。 (1)安装： (1.1) 准备3台机器，分别是 […]
如何部署windows版本的oswatcher
windows上也有os watcher：OSWFW。 目前支持的windows版本是： Windows XP (x86 & x64) Windows 7 (x86 & x64) Windows 8 (x86 & x64) Windows 2003 R1 & […]
mongodb添加arbiter节点
创建mongodb的replica set的时候，只是做成了1主2从，没有做成1主1从1仲裁。这我们将一个几点从replica set中删除，再以仲裁节点的身份加入到replica set中： 1.初始状态：
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shard1ReplSet:PRIMARY> rs.status();rs.status(); { "set" : "shard1ReplSet", "date" : ISODate("2017-02-21T07:48:03.058Z"), "myState" : 1, "term" : NumberLong(1), "heartbeatIntervalMillis" : NumberLong(2000), "optimes" : { "lastCommittedOpTime" : { "ts" : Timestamp(0, 0), "t" : NumberLong(-1) }, "appliedOpTime" : { "ts" : Timestamp(1487663274, 1), "t" : NumberLong(1) }, "durableOpTime" : { "ts" : Timestamp(1487587982, 1), "t" : NumberLong(-1) } }, "members" : [ { "_id" : 0, "name" : "10.13.0.130:22001", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 76672, "optime" : { "ts" : Timestamp(1487663274, 1), "t" : NumberLong(1) }, "optimeDate" : ISODate("2017-02-21T07:47:54Z"), "electionTime" : Timestamp(1487587993, 1), "electionDate" : ISODate("2017-02-20T10:53:13Z"), "configVersion" : 1, "self" : true }, { "_id" : 1, "name" : "10.13.0.131:22001", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 75300, "optime" : { "ts" : Timestamp(1487663274, 1), "t" : NumberLong(1) }, "optimeDurable" : { "ts" : Timestamp(1487587982, 1), "t" : NumberLong(-1) }, "optimeDate" : ISODate("2017-02-21T07:47:54Z"), "optimeDurableDate" : ISODate("2017-02-20T10:53:02Z"), "lastHeartbeat" : ISODate("2017-02-21T07:48:02.150Z"), "lastHeartbeatRecv" : ISODate("2017-02-21T07:48:02.215Z"), "pingMs" : NumberLong(0), "syncingTo" : "10.13.0.132:22001", "configVersion" : 1 }, { "_id" : 2, "name" : "10.13.0.132:22001", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 75300, "optime" : { "ts" : Timestamp(1487663274, 1), "t" : NumberLong(1) }, "optimeDurable" : { "ts" : Timestamp(1487587982, 1), "t" : NumberLong(-1) }, "optimeDate" : ISODate("2017-02-21T07:47:54Z"), "optimeDurableDate" : ISODate("2017-02-20T10:53:02Z"), "lastHeartbeat" : ISODate("2017-02-21T07:48:02.889Z"), "lastHeartbeatRecv" : ISODate("2017-02-21T07:48:01.503Z"), "pingMs" : NumberLong(0), "syncingTo" : "10.13.0.130:22001", "configVersion" : 1 } ], "ok" : 1 } shard1ReplSet:PRIMARY> shard1ReplSet:PRIMARY> shard1ReplSet:PRIMARY> shard1ReplSet:PRIMARY> |
2.删除节点： [cra […]
Oracle并发（CONCURREMT）收集统计信息
对于大表的统计信息收集，我们可以加degree参数，使得扫描大表的时候，进行并行扫描，加快扫描速度。 但是这在收集的时候，还是进行一个表一个表的扫描。并没有并发的扫描各个表。在oracle 11.2.0.2之后，就有了一个参数，可以并发扫描表（或者分区），这就是CONCURRENT参数。你可以通过 […]
Bug Issues Known to cause Wrong Results
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Oracle Database - Enterprise Edition - Version 7.0.16.0 and later Oracle Database - Standard Edition - Version 7.0.16.0 and later Oracle Database - Personal Edition - Version 7.1.4.0 and later Information in this document applies to any platform. |
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This document provides information on bugs known to cause "wrong results". "Wrong results" in this context has quite a broad classification - it may be a performance monitoring view giving slightly misleading information, or may be completely wrong rows returned (or missing) from a query result set. These issues can be particularly difficult to match to a known bug as the symptom often depend on the query. The aim here is to provide a list of bugs known to cause wrong results and to provide both version affected and radio options to trim the list. |
KNOWN BUGS: NB Pr […]
Common X$ dictionary table queries for ORA-4031 investigation
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Oracle Server - Enterprise Edition - Version: 9.2.0.1 to 11.1.0.8 - Release: 9.2 to 11.1 Information in this document applies to any platform. Customers should have limited access to these scripts. There can be database hangs and impacts to performance running these too often. |
PURPOSE: There are a number of x$ queries in various notes […]
Documented Database Bugs With High “Solved SR” Count
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Oracle Database - Enterprise Edition - Version 9.2.0.8 and later |
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This note lists "documented" database bugs that have been marked as the solution to a "high number of Service Requests". For the purpose of this listing: A "documented" bug means one with a bugno.8 KM document created from BugTag data. A "high number of Service Requests" means that there are more than 50 "Solved SR" entries for the bug - ie: all bugs in this doc have > 50 "Solved SR" entries from the SR closure data. It is suggested to restrict the list based on the version of interest, and then use the radio buttons to check on particular features / symptoms / facts linked to the bug descriptions. The list includes some bugs with a "D" in the "NB" column - this is used to denote a bug fix that is DISABLED by default and so a customer may encounter that issue in DB versions where the bug is marked as fixed. |
KNOWN BUGS: NB Prob Bug Fixed Description P IIII 7272646 Linux- […]
Known Issues for Database and Query Performance Reported in 12C
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Oracle Database - Enterprise Edition - Version 12.1.0.1 to 12.1.0.2 [Release 12.1] Information in this document applies to any platform. |
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In recent quarters, during non-code closure bug review for Performance, it was found that more than 50% of duplicates (36,96) closed by Sustaining Engineering (SE) belonged to version 12.1. As a result this document was created to list most commonly reported and share this with Tier-1 engineers so that they could check this before logging any new bugs. Thus the Goal of this document is to provide a list of known bugs reported in 12C for database & SQL performance for support analysts to check before logging new bugs. In addition to the bugs listed in this article, there is also a useful list of Documented Database Bugs With High "Solved SR" Count where a high number of Service Requests means that there are more than 50 "Solved SR" entries for the bug - ie: all bugs in this doc have > 50 "Solved SR" entries.” : Document 2099231.1 Documented Database Bugs With High "Solved SR" Count |
DETAILS: Query Op […]
关于物理Dataguard切换导致索引坏块的问题
在11.2.0.2之后，有一个非常重要的dataguard的patch。在使用物理dataguard环境（包括ADG），进行switchover之后，存在导致index block上的invalid SCNs的坏块问题。 国内已经好几个行业的大客户，都遇到了这个问题。 在index block中的失 […]
swap不足导致ora-4030
客户一个测试环境，一个主机上面运行了很多数据库，某库的程序会时不时报错ora-4030。 加大了pga，然后还检查了ulimit的 data 和 stack都是ulimit。还是报错。 进而检查/var/adm/messages，发现有报错swap不足的情况。 所以，解决方法是加大物理内存，或者加大 […]