You can check I/O statistics and I/O latency distribution by using the polar_stat_io_info and polar_stat_io_latency views.

I/O statistics view

The polar_stat_io_info view displays the I/O statistics.

Column Type Description
filetype text The file type, such as WAL, DATA, and LOG.
fileloc text The local file.
open_count numeric The number of opened files.
open_latency_us double precision The latency of opening files. Unit: microseconds.
close_count numeric The number of closed files.
read_count numeric The number of read files.
write_count numeric The number of written files.
read_throughput numeric The total length of read files. Unit: bytes.
write_throughput numeric The total length of written files. Unit: bytes.
read_latency_us double precision The total latency of reading files. Unit: microseconds.
write_latency_us numeric The total latency of writing files. Unit: microseconds.
seek_count numeric The number of file addressing times.
seek_latency_us double precision The total latency of addressing files. Unit: microseconds.
creat_count numeric The number of created files.
creat_latency_us double precision The total latency of creating files. Unit: microseconds.
fsync_count numeric The number of file synchronization times.
fsync_latency_us double precision The total latency of synchronizing files. Unit: microseconds.
falloc_count numeric The number of falloc files.
falloc_latency_us double precision The total latency of falloc files. Unit: microseconds.

polar_stat_io_latency

The polar_stat_io_latency view displays the I/O latency distribution.

Column Type Description
iokind text The I/O operation type, such as OPEN, CREATE, READ, and WRITE.
num_lessthan200us numeric The number of times when the I/O latency is less than 200 microseconds.
num_lessthan400us numeric The number of times when the I/O latency is less than 400 microseconds.
num_lessthan600us numeric The number of times when the I/O latency is less than 600 microseconds.
num_lessthan800us numeric The number of times when the I/O latency is less than 800 microseconds.
num_lessthan1ms numeric The number of times when the I/O latency is less than 1 millisecond.
num_lessthan10ms numeric The number of times when the I/O latency is less than 10 milliseconds.
num_lessthan100ms numeric The number of times when the I/O latency is less than 100 milliseconds.
num_morethan100ms numeric The number of times when the I/O latency is greater than 100 milliseconds.