Updated on 2024-05-07 GMT+08:00

GLOBAL_DOUBLE_WRITE_STATUS

GLOBAL_DOUBLE_WRITE_STATUS displays doublewrite file status of all instances in the database. It consists of the local_double_write_stat view of each node. Columns in the view on each node are the same.

Table 1 GLOBAL_DOUBLE_WRITE_STATUS columns

Name

Type

Description

node_name

text

Node name.

curr_dwn

bigint

Sequence number of the doublewrite file

curr_start_page

bigint

Start page for restoring the doublewrite file

file_trunc_num

bigint

Number of times that the doublewrite file is reused

file_reset_num

bigint

Number of reset times after the doublewrite file is full

total_writes

bigint

Total number of I/Os of the doublewrite file

low_threshold_writes

bigint

Number of I/Os for writing doublewrite files with low efficiency (the number of I/O flushing pages at a time is less than 16)

high_threshold_writes

bigint

Number of I/Os for writing doublewrite files with high efficiency (the number of I/O flushing pages at a time is more than 421)

total_pages

bigint

Total number of pages that are flushed to the doublewrite file area

low_threshold_pages

bigint

Number of pages that are flushed with low efficiency

high_threshold_pages

bigint

Number of pages that are flushed with high efficiency

file_id

bigint

ID of the current doublewrite file