SPI_execute_plan

SPI_execute_plan_extended
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SPI_execute_plan_extended

SPI_execute_plan_extended — execute a statement prepared by SPI_prepare

Synopsis

int SPI_execute_plan_extended(SPIPlanPtr plan,
                              const SPIExecuteOptions * options)

Description

SPI_execute_plan_extended executes a statement prepared by SPI_prepare or one of its siblings. This function is equivalent to SPI_execute_plan, except that information about the parameter values to be passed to the query is presented differently, and additional execution-controlling options can be passed.

Query parameter values are represented by a ParamListInfo struct, which is convenient for passing down values that are already available in that format. Dynamic parameter sets can also be used, via hook functions specified in ParamListInfo.

Also, instead of always accumulating the result tuples into a SPI_tuptable structure, tuples can be passed to a caller-supplied DestReceiver object as they are generated by the executor. This is particularly helpful for queries that might generate many tuples, since the data can be processed on-the-fly instead of being accumulated in memory.

Arguments

SPIPlanPtr plan: prepared statement (returned by SPI_prepare)
const SPIExecuteOptions * options: struct containing optional arguments

Callers should always zero out the entire options struct, then fill whichever fields they want to set. This ensures forward compatibility of code, since any fields that are added to the struct in future will be defined to behave backwards-compatibly if they are zero. The currently available options fields are:

ParamListInfo params: data structure containing query parameter types and values; NULL if none
bool read_only: true for read-only execution
bool allow_nonatomic: true allows non-atomic execution of CALL and DO statements
bool must_return_tuples: if true, raise error if the query is not of a kind that returns tuples (this does not forbid the case where it happens to return zero tuples)
uint64 tcount: maximum number of rows to return, or 0 for no limit
DestReceiver * dest: DestReceiver object that will receive any tuples emitted by the query; if NULL, result tuples are accumulated into a SPI_tuptable structure, as in SPI_execute_plan
ResourceOwner owner: The resource owner that will hold a reference count on the plan while it is executed. If NULL, CurrentResourceOwner is used. Ignored for non-saved plans, as SPI does not acquire reference counts on those.

Return Value

The return value is the same as for SPI_execute_plan.

When options->dest is NULL, SPI_processed and SPI_tuptable are set as in SPI_execute_plan. When options->dest is not NULL, SPI_processed is set to zero and SPI_tuptable is set to NULL. If a tuple count is required, the caller's DestReceiver object must calculate it.