ApdbCassandraSchema

class lsst.dax.apdb.ApdbCassandraSchema(session: cassandra.cluster.Session, schema_file: str, extra_schema_file: Optional[str] = None, prefix: str = '', packing: str = 'none', time_partition_tables: bool = False)

Bases: lsst.dax.apdb.ApdbSchema

Class for management of APDB schema.

Parameters:

session : cassandra.cluster.Session

Cassandra session object

schema_file : str

Name of the YAML schema file.

extra_schema_file : str, optional

Name of the YAML schema file with extra column definitions.

prefix : str, optional

Prefix to add to all schema elements.

packing : str

Type of packing to apply to columns, string “none” disable packing, any other value enables it.

time_partition_tables : bool

If True then schema will have a separate table for each time partition.

Methods Summary

clusteringColumns(table_name)	Return a list of columns used for clustering.
getColumnMap(table_name)	Returns mapping of column names to Column definitions.
makeSchema(drop, part_range, int]] = None)	Create or re-create all tables.
packedColumns(table_name)	Return set of columns that are packed into BLOB.
partitionColumns(table_name)	Return a list of columns used for table partitioning.
tableName(table_name)	Return Cassandra table name for APDB table.

Methods Documentation

clusteringColumns(table_name: lsst.dax.apdb.apdbSchema.ApdbTables) → List[str]

Return a list of columns used for clustering.

Parameters:

table_name : ApdbTables

Table name in APDB schema

Returns:

columns : list of str

Names of columns for used for partitioning.

getColumnMap(table_name: lsst.dax.apdb.apdbSchema.ApdbTables) → Mapping[str, lsst.dax.apdb.apdbSchema.ColumnDef]

Returns mapping of column names to Column definitions.

Parameters:

table_name : ApdbTables

One of known APDB table names.

Returns:

column_map : dict

Mapping of column names to ColumnDef instances.

makeSchema(drop: bool = False, part_range: Optional[Tuple[int, int]] = None) → None

Create or re-create all tables.

Parameters:

drop : bool

If True then drop tables before creating new ones.

part_range : tuple [ int ] or None

Start and end partition number for time partitions, end is not inclusive. Used to create per-partition DiaObject, DiaSource, and DiaForcedSource tables. If None then per-partition tables are not created.

packedColumns(table_name: lsst.dax.apdb.apdbSchema.ApdbTables) → List[lsst.dax.apdb.apdbSchema.ColumnDef]

Return set of columns that are packed into BLOB.

Parameters:

table_name : ApdbTables

Name of the table.

Returns:

columns : list [ ColumnDef ]

List of column definitions. Empty list is returned if packing is not configured.

partitionColumns(table_name: lsst.dax.apdb.apdbSchema.ApdbTables) → List[str]

Return a list of columns used for table partitioning.

Parameters:

table_name : ApdbTables

Table name in APDB schema

Returns:

columns : list of str

Names of columns for used for partitioning.

tableName(table_name: lsst.dax.apdb.apdbSchema.ApdbTables) → str

Return Cassandra table name for APDB table.