Query Reviewer

QueryReviewer is an advanced SQL query analyzer. It accomplishes the following goals:

View all EXPLAIN output for all SELECT queries to generate a page (and optionally SHOW PROFILE ALL)
Rate a page’s SQL usage into one of three categories: OK, WARNING, CRITICAL
Attach meaningful warnings to individual queries, and collections of queries
Display interactive summary on page

All you have to do is install it. You can optionally run: rake query_reviewer:setup

Which will create config/query_reviewer.yml, see below for what these options mean. If you don’t have a config file, the plugin will use the default in vendor/plugins/query_reviewer.

Configuration

The configuration file allows you to set configuration parameters shared across all rails environment, as well as overriding those shared parameteres with environment-specific parameters (such as disabling analysis on production!)

enabled: whether any output or query analysis is performed. Set this false in production!
inject_view: controls whether the output automatically is injected before the </body> in HTML output.
profiling: when enabled, runs the MySQL SET PROFILING=1 for queries longer than the warn_duration_threshold / 2.0
production_data: whether the duration of a query should be taken into account (if you don’t have real data, don’t let query duration effect you!)

stack_trace_lines: number of lines of call stack to include in the “short” version of the stack trace
trace_includes_vendor: whether the “short” verison of the stack trace should include files in /vendor
trace_includes_lib: whether the “short” verison of the stack trace should include files in /lib

warn_severity: the severity of problem that merits “WARNING” status
critical_severity: the severity of problem that merits “CRITICAL” status

warn_query_count: the number of queries in a single request that merits “WARNING” status
critical_query_count: the number of queries in a single request that merits “CRITICAL” status

warn_duration_threshold: how long a query must take in seconds (float) before it’s considered “WARNING”
critical_duration_threshold: how long a query must take in seconds (float) before it’s considered “CRITICIAL”