…Query | 74 | Waiting for global read lock | insert into C values (“a”,1) | 0 | 0 | 1 | | 10304 | root | localhost | dumptest | Field List | 15 | Waiting for…
Post: Beware large Query_Cache sizes
March 23, 2007 By 3 Comments
…queries being invalidated by single insert – this typically happens if you have rare bulk loads rather than constant insertion…query cache size – smaller values do not have such problems but also often will be less efficient. In many…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…INNODB STATUS many values are per second. If you’re planning to use these values make …for insert buffer merges, asynchronous log flushes, read-ahead and flushing of dirty buffers. Normal reads originated from query… be flushed by checkpointing process and single page – independent page writes. We can…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…scan the whole table to query for information about yesterday. …values for various attributes, for example; or the presence or absence of values…-scale database server for the initial insertion, because you can…single row created from many rows, and if the many rows don’t match completely, the single…
Post: MySQL caching methods and tips
April 4, 2011 By 4 Comments
… operational costs, so caches provide real value by avoiding using those resources. You… many round trips Asking the cache for many different pieces of data to satisfy a single…can be indexed appropriately for your queries. Using INSERT .. SELECT for summary tables The INSERT .. SELECT approach works…
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 4 Comments
… to determine how many concurrency tickets a query uses, making …INSERT w/PRIMARY KEY defined: Number of rows inserted – 1 INSERT w/FOREIGN KEY constraint: Number of rows inserted…500, then all of the single row PK lookups will …value of 4,294,967,295 this has the potential to block other queries for…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
… is: for small tables, everything can reside within a single extent. For big … they were not matched by query where clause when it was… Q16: How Innodb decided how many pages to flush at each …INSERT with multiple values? We build up INSERTS on our clients and insert values 50 or so at a time. HT: For…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…INSERT-only workloads, and their are other optimizations that can be applied to views that are based on only a single…Query works only on sets Shard-Query takes relational algebra to its logical maximum conclusion, splitting a problem up into many…
Post: MySQL Server Memory Usage
May 17, 2006 By 18 Comments
…for exampe to handle subqueries. For some special queries memory usage might be even larger – bulk inserts may allocate bulk_insert…values to run some queries. There can be mutiple key caches. Multiple key caches can be created to accomodate query executions Query…. Single connection may have many…
Post: MySQL File System Fragmentation Benchmarks
March 21, 2008 By 28 Comments
… queries are going to be affected same way, for example point select reading single …for as simple command as “ls” even though loadavg was about 1. In the process list I could see some single value insert…overhead for insert with many tables. The read performance, which is the main measurement for …
