25.12.15 Performance Schema Summary Tables (original) (raw)

25.12.15 Performance Schema Summary Tables

Summary tables provide aggregated information for terminated events over time. The tables in this group summarize event data in different ways.

Each summary table has grouping columns that determine how to group the data to be aggregated, and summary columns that contain the aggregated values. Tables that summarize events in similar ways often have similar sets of summary columns and differ only in the grouping columns used to determine how events are aggregated.

Summary tables can be truncated withTRUNCATE TABLE. Generally, the effect is to reset the summary columns to 0 orNULL, not to remove rows. This enables you to clear collected values and restart aggregation. That might be useful, for example, after you have made a runtime configuration change. Exceptions to this truncation behavior are noted in individual summary table sections.

Wait Event Summaries

Table 25.3 Performance Schema Wait Event Summary Tables

Stage Summaries

Table 25.4 Performance Schema Stage Event Summary Tables

Statement Summaries

Transaction Summaries

Table 25.6 Performance Schema Transaction Event Summary Tables

Object Wait Summaries

File I/O Summaries

Table I/O and Lock Wait Summaries

Socket Summaries

Memory Summaries

Status Variable Summaries

Table 25.12 Performance Schema Error Status Variable Summary Tables