This topic describes the performance metric Transaction table read request hits of OceanBase Database tenants. The Transaction table read request hits metric indicates the number of hits of table read requests per second of an OceanBase Database tenant. This metric consists of the following five sub-metrics: Mini_Cache_Hit_Count, KV_Cache_Hit_Count, TX_CTX_Hit_Count, TX_Data_Memtable_Hit_Count, and TX_Data_SStable_Hit_Count. You can specify a statistical scope to query the number of hits of table read requests in a single zone or on a single OBServer node of a tenant.
Mini_Cache_Hit_Count
Definition
The number of times that table read requests hit the mini cache.
Description
| Metric | Metric name | Unit |
|---|---|---|
| Mini_Cache_Hit_Count | tx_data_hit_mini_cache_count | times/s |
Calculation expression
sum(rate(ob_sysstat{stat_id="30082",@LABELS}[@INTERVAL])) by (@GBLABELS)
SQL statements for metric collection
If you use OceanBase Database V4.0 or later, execute the following statement:
select /* MONITOR_AGENT */ con_id tenant_id, stat_id, value from v$sysstat where stat_id IN (30082) and (con_id > 1000 or con_id = 1) and class < 1000
KV_Cache_Hit_Count
Definition
The number of times that table read requests hit the KVCache.
Description
| Metric | Metric name | Unit |
|---|---|---|
| KV_Cache_Hit_Count | tx_data_hit_kv_cache_count | times/s |
Calculation expression
sum(rate(ob_sysstat{stat_id="30083",@LABELS}[@INTERVAL])) by (@GBLABELS)
SQL statements for metric collection
If you use OceanBase Database V4.0 or later, execute the following statement:
select /* MONITOR_AGENT */ con_id tenant_id, stat_id, value from v$sysstat where stat_id IN (30083) and (con_id > 1000 or con_id = 1) and class < 1000
TX_CTX_Hit_Count
Definition
The number of times that table read requests hit the transaction context table.
Description
| Metric | Metric name | Unit |
|---|---|---|
| TX_CTX_Hit_Count | tx_data_read_tx_ctx_count | times/s |
Calculation expression
sum(rate(ob_sysstat{stat_id="30084",@LABELS}[@INTERVAL])) by (@GBLABELS)
SQL statements for metric collection
If you use OceanBase Database V4.0 or later, execute the following statement:
select /* MONITOR_AGENT */ con_id tenant_id, stat_id, value from v$sysstat where stat_id IN (30084) and (con_id > 1000 or con_id = 1) and class < 1000
TX_Data_Memtable_Hit_Count
Definition
The number of times that table read requests hit the MemTable.
Description
| Metric | Metric name | Unit |
|---|---|---|
| TX_Data_Memtable_Hit_Count | tx_data_read_tx_data_memtable_count | times/s |
Calculation expression
sum(rate(ob_sysstat{stat_id="30085",@LABELS}[@INTERVAL])) by (@GBLABELS)
SQL statements for metric collection
If you use OceanBase Database V4.0 or later, execute the following statement:
select /* MONITOR_AGENT */ con_id tenant_id, stat_id, value from v$sysstat where stat_id IN (30085) and (con_id > 1000 or con_id = 1) and class < 1000
TX_Data_SStable_Hit_Count
Definition
The number of times that table read requests hit the SSTable.
Description
| Metric | Metric name | Unit |
|---|---|---|
| TX_Data_SStable_Hit_Count | tx_data_read_tx_data_sstable_count | times/s |
Calculation expression
sum(rate(ob_sysstat{stat_id="30086",@LABELS}[@INTERVAL])) by (@GBLABELS)
SQL statements for metric collection
If you use OceanBase Database V4.0 or later, execute the following statement:
select /* MONITOR_AGENT */ con_id tenant_id, stat_id, value from v$sysstat where stat_id IN (30086) and (con_id > 1000 or con_id = 1) and class < 1000