ConstReadonlyCONTINUOUS: "CONTINUOUS"The pipeline processes new source-table data continuously to keep the index fresh.
ReadonlyPIPELINE_TYPE_UNSPECIFIED: "PIPELINE_TYPE_UNSPECIFIED"Default value; unset. Rejected by the backend on create — callers must pick
TRIGGERED or CONTINUOUS. Distinct from the legacy enum's TRIGGERED = 0 default so
an unset wire value is not silently coerced to TRIGGERED.
ReadonlyTRIGGERED: "TRIGGERED"The pipeline runs once per trigger, refreshing the source table a single time.
Pipeline execution mode for a Delta Sync index. Required on create for Delta Sync indexes; the legacy backend rejects an unset value with INVALID_PARAMETER_VALUE.
TRIGGERED: the pipeline stops after refreshing the source table once, using the data available when the update started.CONTINUOUS: the pipeline processes new data as it arrives in the source table to keep the index fresh.