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Search Results for: select row number

Identifying useful info from MySQL row-based binary logs

As a MySQL DBA/consultant, it is part of my job to decode the MySQL binary logs – and there are a number of reasons for doing that. In this post, I’ll explain how you can …

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Looking deeper into InnoDB’s problem with many row versions

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single …

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MySQL 5.6 Full Text Search Throwdown: Webinar Q&A

Yesterday (Oct. 22) I gave a presentation titled “MySQL 5.6 Full Text Search Throwdown.” If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and …

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Do not trust vmstat IOwait numbers

I’ve been running a benchmark today on my old test box with conventional hard drives (no raid with BBU) and noticed something unusual in the CPU utilization statistics being reported. The benchmark was run like …

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How rows_sent can be more than rows_examined?

When looking at queries that are candidates for optimization I often recommend that people look at rows_sent and rows_examined values as available in the slow query log (as well as some other places). If rows_examined …

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FictionPress Selects TokuDB for Consistent Performance and Fast Disaster Recovery

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FictionPress Issues addressed: Support complex and efficient indexes at 100+ million rows. Predicable and consistent performance regardless of data size growth. Fast recovery. Ensuring Predictable Performance at Scale The Company:  FictionPress operates both FictionPress.com and …

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SELECT UNION Results INTO OUTFILE

Here’s a quick tip I know some of us has overlooked at some point. When doing SELECT … UNION SELECT, where do you put the the INTO OUTFILE clause? On the first SELECT, on the …

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Online Advertiser Intent Media Selects TokuDB over InnoDB and NoSQL for Big Data Ad-Hoc Analysis

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Intent Media Issue addressed: Ad hoc analytics on clickstream data arriving too fast for InnoDB or NoSQL to handle. TokuDB powers an online advertising application The Company: Headquartered in New York, Intent Media is a …

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Color code your performance numbers

When analyzing how good or bad response time is it is not handy to look at the averages, min or max times – something what is easily computed using built in aggregate functions. We most …

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Debugging problems with row based replication

MySQL 5.1 introduces row based binary logging. In fact, the default binary logging format in GA versions of MySQL 5.1 is ‘MIXED’ STATEMENT*;   The binlog_format  variable can still be changed per sessions which means …

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