Common request options for various APIs.
JSON representation |
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{
"priority"
:
enum (
|
Fields | |
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priority
|
Priority for the request. |
requestTag
|
A per-request tag which can be applied to queries or reads, used for statistics collection. Both |
transactionTag
|
A tag used for statistics collection about this transaction. Both |
Priority
The relative priority for requests. Note that priority isn't applicable for sessions.beginTransaction
.
The priority acts as a hint to the Cloud Spanner scheduler and doesn't guarantee priority or order of execution. For example:
- Some parts of a write operation always execute at
PRIORITY_HIGH
, regardless of the specified priority. This can cause you to see an increase in high priority workload even when executing a low priority request. This can also potentially cause a priority inversion where a lower priority request is fulfilled ahead of a higher priority request. - If a transaction contains multiple operations with different priorities, Cloud Spanner doesn't guarantee to process the higher priority operations first. There might be other constraints to satisfy, such as the order of operations.
Enums | |
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PRIORITY_UNSPECIFIED
|
PRIORITY_UNSPECIFIED
is equivalent to PRIORITY_HIGH
. |
PRIORITY_LOW
|
This specifies that the request is low priority. |
PRIORITY_MEDIUM
|
This specifies that the request is medium priority. |
PRIORITY_HIGH
|
This specifies that the request is high priority. |