Frankly I don’t know why MYSQL default transaction isolation to REPEATABLE-READ Oracle default to READ-COMMITTED. REPEATABLE-READ is too strict and too expensive in term of purging undo segments.
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
… transaction spawns multiple databases you need multiple log flushes on commit, plus ether you use XA to synchronize these which is… updated the row to commit and then fail with “ERROR 1020 (HY000): Record has changed since last read in table ‘t’” error… pages recovered from it after it was implemented. Speaking with Oracle and PostgreSQL developers it looks like they all acknowledge this…
Post: Bug#12704861
November 20, 2011 By 1 Comment
… id: marko.makela@oracle.com-20110616072721-8bo92ctixq6eqavr ). I mention this bug as it is mentioned in the commit message for the fix… the full text of Marko’s commit message for the fix as it’s interesting reading for those of us who are… address was that when we did mtr_commit() the BLOB writes before the mtr_commit() of the update, the new BLOB pages…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…at a time. The read aio thread will normally read all the 64 page read requests in a readahead… different applications work best on different database brands. Oracle‘s main database has a very competent …problem to the SDD wear leveling: if you commit 1000 transactions per second, then you write 1000…
Post: When would you use SAN with MySQL ?
March 9, 2009 By 18 Comments
…is especially popular among people got used to Oracle or other Enterprise database systems which are … on the server too which will make read caching more efficient in its memory while…commit too. MySQL also has broken group commit (which we have partial fix for) meaning concurrent transaction commits…
Comment: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
… are environment related – log flushing on transaction commit, size of log files etc. Regarding design -…current Limits section though. Isolation Modes: Innodb, Oracle, PostgreSQL also support MVCC but frequently …about blob materialization – Innodb also will only read the blob if it is accessed. …
Post: Watch out for Marketing benchmarks
August 23, 2006 By 7 Comments
… developers would understand it. For non developers reading this article for some reason – think about following … not fixed, others, such as broken group commit could have been handled better. Same applies … to avoid directly comparable results – for example Oracle and Microsoft would run TPC-C on …
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
… (equivalent to innodb_flush_log_at_trx_commit=2). A major change was completed at …. Morgan notes: As well as Adaptive Checkpointing, Oracle has also been working on Adaptive Flushing … isolation paradigm between the two engines. REPEATABLE READ is often preferred over SERIALIZABLE mode because …
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… and most accurate approach but it does not work in Oracle MySQL Server. set userstat_running=1 and run following query… ROWS_UPDATED: 127576 TABLE_ROWS_READ: 4085689 SELECT_COMMANDS: 0 UPDATE_COMMANDS: 119127 OTHER_COMMANDS: 89557 COMMIT_TRANSACTIONS: 90259 ROLLBACK_TRANSACTIONS: 0… send event | NULL | | 801813 | system user | | NULL | Connect | 0 | Has read all relay log; waiting for the slave I/O thread…
Post: Review of Virident FlashMAX MLC cards
November 10, 2011 By 14 Comments
…. However, the drawback is that 25nm has worse reading and writing latencies, compared to previous generations. However, … in benchmarks include: Server: Cisco UCS C250, running Oracle Linux 6.1 and Percona Server 5.5…._size=174GB and innodb_flush_log_at_trx_commit=1 As in all my recent benchmarks, I …
