Different results between metric and Oracle query #457
Description
In oracledb_exporter, I noticed that the values collected by the metric on Prometheus are different from those obtained from the same select on the database.
Could anyone tell me why? Where am I going wrong?
Here is the metric from the default-metrics.toml:
[[metric]]
context = "tablespace"
labels = [ "tablespace", "type" ]
metricsdesc = { bytes = "Generic counter metric of tablespaces bytes in Oracle.", max_bytes = "Generic counter metric of tablespaces max bytes in Oracle.", free = "Generic counter metric of tablespaces free bytes in Oracle." }
request = '''
SELECT
dt.tablespace_name as tablespace,
dt.contents as type,
dt.block_size * dtum.used_space as bytes,
dt.block_size * dtum.tablespace_size as max_bytes,
dt.block_size * (dtum.tablespace_size - dtum.used_space) as free
FROM dba_tablespace_usage_metrics dtum, dba_tablespaces dt
WHERE dtum.tablespace_name = dt.tablespace_name
ORDER by tablespace
'''
From Prometheus, I get the following results, for example:
oracledb_tablespace_bytes{instance="xxx.xx.x.xx:9161", job="oracle_exporter", tablespace="SYSAUX", type="PERMANENT"} 872939520
oracledb_tablespace_bytes{instance="xxx.xx.x.xx:9161", job="oracle_exporter", tablespace="SYSTEM", type="PERMANENT"} 1020067840
However, on the database, the values are:
TABLESPACE TYPE BYTES MAX_BYTES FREE
SYSAUX PERMANENT 467468288 2.9548E+10 2.9081E+10
SYSTEM PERMANENT 527171584 2.9548E+10 2.9021E+10
Why is the BYTES value different?
Thank you.