健哥的数据花园

2013年8月2日

摘要：接前文初步学习pg_control文件之十三看如下几个：/* * Parameter settings that determine if the WAL can be used for archival * or hot standby. */ int wal_level; int MaxConnections; int max_prepared_xacts; int max_locks_per_xact;PostgreSQL中多次用到了函数数组：/* ... 阅读全文

posted @ 2013-08-02 11:25 健哥的数据花园阅读(838) 评论(0) 推荐(0) 编辑

初步学习pg_control文件之十三

摘要：接前文，初步学习pg_control文件之十二看这个： * backupStartPoint is the redo pointer of the backup start checkpoint, if * we are recovering from an online backup and haven't reached the end of * backup yet. It is reset to zero when the end of backup is reached, and * we mustn't start up before that. A ... 阅读全文

posted @ 2013-08-02 10:14 健哥的数据花园阅读(343) 评论(0) 推荐(0) 编辑

fsync体会

摘要：看这个链接：http://www.postgresql.org/docs/9.1/static/runtime-config-wal.html是这样说的：fsync (boolean)If this parameter is on, the PostgreSQL server will try to make sure that updates are physically written to disk, by issuing fsync() system calls or various equivalent methods (see wal_sync_method). This ensu 阅读全文

posted @ 2013-08-02 09:57 健哥的数据花园阅读(745) 评论(0) 推荐(0) 编辑

2013年8月1日

初步学习pg_control文件之十二

摘要：接前问，初步学习pg_control文件之十一，再来看下面这个XLogRecPtr minRecoveryPoint;看其注释： * minRecoveryPoint is updated to the latest replayed LSN whenever we * flush a data change during archive recovery. That guards against * starting archive recovery, aborting it, and restarting with an earlier * stop ... 阅读全文

posted @ 2013-08-01 17:06 健哥的数据花园阅读(995) 评论(0) 推荐(0) 编辑

初步学习pg_control文件之十一

摘要：接前文初步学习pg_control文件之十，再看这个XLogRecPtr prevCheckPoint; /* previous check point record ptr */发生了checkpoint的时候，肯定要处理的：/* * Perform a checkpoint --- either during shutdown, or on-the-fly * * flags is a bitwise OR of t... 阅读全文

posted @ 2013-08-01 15:10 健哥的数据花园阅读(761) 评论(0) 推荐(0) 编辑

初步学习pg_control文件之十

摘要：接前文初步学习pg_control文件之九看下面这个XLogRecPtr checkPoint; /* last check point record ptr */看看这个pointer究竟保留了什么初始化的时候：/* * This func must be called ONCE on system install. It creates pg_control * and the initial XLOG segment. ... 阅读全文

posted @ 2013-08-01 13:53 健哥的数据花园阅读(800) 评论(0) 推荐(0) 编辑

初步学习pg_control文件之九

摘要：接前文，初步学习pg_control文件之八来看这个：pg_time_t time; /* time stamp of last pg_control update */当初初始化的时候，是这样的：/* * This func must be called ONCE on system install. It creates pg_control * and the initial XLOG segment. */voidBootStrapXLOG(void){ ... CheckPoint checkPoint; ... check... 阅读全文

posted @ 2013-08-01 12:28 健哥的数据花园阅读(927) 评论(0) 推荐(0) 编辑

初步学习pg_control文件之八

摘要：接前文初步学习pg_control文件之七继续看：catalog_version_no代码如下：static voidWriteControlFile(void){ ... /* * Initialize version and compatibility-check fields */ ControlFile->pg_control_version = PG_CONTROL_VERSION; ControlFile->catalog_version_no = CATALOG_VERSION_NO; ...}在catversio... 阅读全文

posted @ 2013-08-01 09:58 健哥的数据花园阅读(489) 评论(0) 推荐(0) 编辑

初步学习pg_control文件之七

摘要：接前文初步学习pg_control文件之六看 pg_control_version以PostgreSQL9.1.1为了，其HISTORY文件中有如下的内容：Release 9.1.2Release Date: 2011-12-05This release contains a variety of fixes from 9.1.1. For informationabout new features in the 9.1 major release, see the Section calledRelease 9.1.早就写死了:static voidWriteControlFile(void 阅读全文

posted @ 2013-08-01 09:13 健哥的数据花园阅读(578) 评论(0) 推荐(0) 编辑

2013年7月31日

初步学习pg_control文件之六

摘要：接前文：初步学习pg_control文件之五，DB_IN_ARCHIVE_RECOVERY何时出现？看代码：如果recovery.conf文件存在，则返回InArchiveRecovery = true。/* * See if there is a recovery command file (recovery.conf), and if so * read in parameters for archive recovery and XL... 阅读全文

posted @ 2013-07-31 16:36 健哥的数据花园阅读(814) 评论(0) 推荐(0) 编辑

健哥的数据花园

公告