DimensionRecordQueryResults

final class lsst.daf.butler.DimensionRecordQueryResults(driver: QueryDriver, tree: QueryTree, spec: DimensionRecordResultSpec)

Bases: QueryResultsBase

A query for DimensionRecord results.

Parameters:

driverQueryDriver

Implementation object that knows how to actually execute queries.

treeQueryTree

Description of the query as a tree of joins and column expressions. The instance returned directly by the Butler._query entry point should be constructed via make_unit_query_tree.

specDimensionRecordResultSpec

Specification of the query result rows, including output columns, ordering, and slicing.

Notes

This class should never be constructed directly by users; use Query.dimension_records instead.

Attributes Summary

element

Methods Summary

count(*[, exact, discard])	Count the number of rows this query would return.
iter_set_pages()	Return an iterator over individual pages of results as set-backed collections.
iter_table_pages()	Return an iterator over individual pages of results as table-backed collections.

Attributes Documentation

element

Methods Documentation

count(*, exact: bool = True, discard: bool = False) → int

Count the number of rows this query would return.

Parameters:

exactbool, optional

If True, run the full query and perform post-query filtering if needed to account for that filtering in the count. If False, the result may be an upper bound.

discardbool, optional

If True, compute the exact count even if it would require running the full query and then throwing away the result rows after counting them. If False, this is an error, as the user would usually be better off executing the query first to fetch its rows into a new query (or passing exact=False). Ignored if exact=False.

Returns:

countint

The number of rows the query would return, or an upper bound if exact=False.

iter_set_pages() → Iterator[DimensionRecordSet]

Return an iterator over individual pages of results as set-backed collections.

Yields:

tableDimensionRecordSet

A set-backed collection of dimension records.

iter_table_pages() → Iterator[DimensionRecordTable]

Return an iterator over individual pages of results as table-backed collections.

Yields:

tableDimensionRecordTable

A table-backed collection of dimension records.