Package io.trino.operator.table.json.execution

Interface JsonTableProcessingFragment

All Known Implementing Classes:

FragmentCross, FragmentLeaf, FragmentSingle, FragmentUnion

public interface JsonTableProcessingFragment

Method Summary

Modifier and Type	Method	Description
int[]	getOutputLayout()	Returns an array containing indexes of columns produced by the fragment within all columns produced by json_table.
boolean	getRow()	Tries to produce output values for all columns included in the Fragment, and stores them in corresponding positions in `newRow`.
void	reset(com.fasterxml.jackson.databind.JsonNode item, Page input, int position)	Prepares the Fragment to produce rows for the new JSON item.
default void	resetRoot(com.fasterxml.jackson.databind.JsonNode item, Page input, int position, Object[] pathParameters)	Prepares the root Fragment to produce rows for the new JSON item and new set of path parameters.

Method Details

reset

void reset(com.fasterxml.jackson.databind.JsonNode item,
 Page input,
 int position)

Prepares the Fragment to produce rows for the new JSON item. Note: This method must be called for each new JSON item. Due to nesting, there might be multiple JSON items to process for a single position in the input page. Therefore, input and position may not change for subsequent calls.

Parameters:

item - the new JSON item

input - the input Page currently processed by json_table function

position - the currently processed position in the input page

resetRoot

default void resetRoot(com.fasterxml.jackson.databind.JsonNode item,
 Page input,
 int position,
 Object[] pathParameters)

Prepares the root Fragment to produce rows for the new JSON item and new set of path parameters. Note: at the root level, there is one JSON item and one set of path parameters to process for each position in the input page.

Parameters:

item - the new JSON item

input - the input Page currently processed by json_table function

position - the currently processed position in the input page

pathParameters - JSON path parameters for the top-level JSON path

getRow

boolean getRow()

Tries to produce output values for all columns included in the Fragment, and stores them in corresponding positions in `newRow`. Note: According to OUTER or UNION semantics, some values might be null-padded instead of computed. Note: a single JSON item might result in multiple output rows. To fully process a JSON item, the caller must: - reset the Fragment with the JSON item - call getRow() and collect output rows as long as `true` is returned If `false` is returned, there is no output row available, and the JSON item is fully processed

Returns:

true if row was produced, false if row was not produced (Fragment is finished)

getOutputLayout

int[] getOutputLayout()

Returns an array containing indexes of columns produced by the fragment within all columns produced by json_table.