… be really bad, especially in some cases and having them dynamic was first major step in making sure problems at least… natural step I would like to see taken is having MySQL to chose sensible values for them automatically, based on system… it silly for example MySQL would use the same sort_buffer_size whenever there is only one query running and so there…
Post: SQL Injection Questions Followup
July 26, 2012 By 2 Comments
… uses dynamic SQL in stored procedures extensively. They found that it was awkward because of the limits of the procedure language MySQL… moves too much computation load onto their database server. Their MySQL server became CPU-bound, while their multiple PHP application servers… database must be protected again if you use query results in a subsequent SQL query, then you should be able to store…
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
… – MySQL does not really have the special “plan generating” step, instead plan is generated as a part of query execution, sometimes being dynamic based on data. With EXPLAIN MySQL kind of simulates execution but it… about functions cost Since MySQL 5.0 you may use user functions in your query which may also perform queries themselves. These actions…
Post: MySQL Storage Engines - PBXT
May 14, 2007 By 6 Comments
… for many applications if implemented well. It is too bad MySQL Users Conference only allowed 45 minutes for Storage Engine presentations… each rows has fixed data part and dynamic data parts stored in separate files. Dynamic length part is stored in file called… is only worse case scenario – for many queries you will not need to touch dynamic length part and row pointer file should…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
… dynamic comments in the query, have extra space or use different case – these would be different queries for query cache. Only SELECT queries …query cache. Now lets speak a bit about Query Cache configuration and mainance. MySQL Manual is pretty good on this: Query Cache Query Cache Status Query…
Post: The Optimization That (Often) Isn't: Index Merge Intersection
December 14, 2012 By 6 Comments
Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that… configuration setting and disable index_merge_intersection. It’s a dynamically-adjustable setting and can be modified globally or per-session…_type) that is the one that MySQL should be looking at, we can rewrite the query like so, with the following result…
Post: Air traffic queries in InfiniDB: early alpha
November 2, 2009 By 19 Comments
…, it shows Name: ontime Engine: InfiniDB Version: 10 Row_format: Dynamic Rows: 2000 Avg_row_length: 0 Data_length: 0 Max…. Other queries: (again look on comparison with other engines in Google Spreadsheet or in summary table at the bottom) Query Q1: mysql> SELECT… Origin ORDER BY c DESC LIMIT 10; 4.96 sec Query Q4: mysql> SELECT Carrier, count(*) FROM ontime WHERE DepDelay > 10 AND…
Post: MySQL Session variables and Hints
December 28, 2006 By 2 Comments
MySQL has two ways to find tune execution of particular query. First is MySQL Hints, such as SQL_BIG_RESULT, STRAIGHT_JOIN, FORCE INDEX etc. You place these directly into the query… easier to simply change the query (especially if it is not created dynamically some complex way) – adding extra MySQL calls with possibly their…
Post: Wishes for new "Pure PHP" MySQL driver
October 28, 2006 By 17 Comments
… me. Arrays in Prepared Statements Dealing with certain types of queries, ie queries with IN is so painful with prepared statements – I… run query several times per page. I however would like to go further and have TTL based client cache with dynamic back… in many cases. Multiple concurrent queries I would like to be able to run multiple queries for multiple MySQL connections at once. For…
Post: Data compression in InnoDB for text and blob fields
May 30, 2012 By 2 Comments
… many heavily utilized TEXT fields with some read queries exceeding 500MB (!!), and stored in a 100GB table. … in overflow pages. COMPACT became the default after MySQL 5.0.3 and has a more compact …. Also note that you need to enable the dynamic variable innodb_file_format=BARRACUDA (don’t forget …
