DimensionRecordStorage¶
- class lsst.daf.butler.registry.interfaces.DimensionRecordStorage¶
Bases:
ABC
An abstract base class that represents a way of storing the records associated with a single
DimensionElement
.Concrete
DimensionRecordStorage
instances should generally be constructed via a call tosetupDimensionStorage
, which selects the appropriate subclass for each element according to its configuration.All
DimensionRecordStorage
methods are pure abstract, even though in some cases a reasonable default implementation might be possible, in order to better guarantee all methods are correctly overridden. All of these potentially-defaultable implementations are extremely trivial, so asking subclasses to provide them is not a significant burden.Attributes Summary
The element whose records this instance managers (
DimensionElement
).Methods Summary
Clear any in-memory caches held by the storage instance.
Return tables used for schema digest.
fetch
(dataIds)Retrieve records from storage.
insert
(*records[, replace, skip_existing])Insert one or more records into storage.
join
(builder, *[, regions, timespans])Add the dimension element's logical table to a query under construction.
sync
(record[, update])Synchronize a record with the database, inserting it only if it does not exist and comparing values if it does.
Attributes Documentation
- element¶
The element whose records this instance managers (
DimensionElement
).
Methods Documentation
- abstract clearCaches() None ¶
Clear any in-memory caches held by the storage instance.
This is called by
Registry
when transactions are rolled back, to avoid in-memory caches from ever containing records that are not present in persistent storage.
- abstract digestTables() Iterable[Table] ¶
Return tables used for schema digest.
- Returns:
- tables
Iterable
[sqlalchemy.schema.Table
] Possibly empty set of tables for schema digest calculations.
- tables
- abstract fetch(dataIds: DataCoordinateIterable) Iterable[DimensionRecord] ¶
Retrieve records from storage.
- Parameters:
- dataIds
DataCoordinateIterable
Data IDs that identify the records to be retrieved.
- dataIds
- Returns:
- records
Iterable
[DimensionRecord
] Record retrieved from storage. Not all data IDs may have corresponding records (if there are no records that match a data ID), and even if they are, the order of inputs is not preserved.
- records
- abstract insert(*records: DimensionRecord, replace: bool = False, skip_existing: bool = False) None ¶
Insert one or more records into storage.
- Parameters:
- records
One or more instances of the
DimensionRecord
subclass for the element this storage is associated with.- replace: `bool`, optional
If
True
(False
is default), replace existing records in the database if there is a conflict.- skip_existing
bool
, optional If
True
(False
is default), skip insertion if a record with the same primary key values already exists.
- Raises:
- TypeError
Raised if the element does not support record insertion.
- sqlalchemy.exc.IntegrityError
Raised if one or more records violate database integrity constraints.
Notes
As
insert
is expected to be called only by aRegistry
, we rely onRegistry
to provide transactionality, both by using a SQLALchemy connection shared with theRegistry
and by relying on it to callclearCaches
when rolling back transactions.
- abstract join(builder: QueryBuilder, *, regions: NamedKeyDict[DimensionElement, sqlalchemy.sql.ColumnElement] | None = None, timespans: NamedKeyDict[DimensionElement, TimespanDatabaseRepresentation] | None = None) sqlalchemy.sql.FromClause ¶
Add the dimension element’s logical table to a query under construction.
This is a visitor pattern interface that is expected to be called only by
QueryBuilder.joinDimensionElement
.- Parameters:
- builder
QueryBuilder
Builder for the query that should contain this element.
- regions
NamedKeyDict
, optional A mapping from
DimensionElement
to a SQLAlchemy column containing the region for that element, which should be updated to include a region column for this element if one exists. IfNone
,self.element
is not being included in the query via a spatial join.- timespan
NamedKeyDict
, optional A mapping from
DimensionElement
to aTimespan
of SQLALchemy columns containing the timespan for that element, which should be updated to include timespan columns for this element if they exist. IfNone
,self.element
is not being included in the query via a temporal join.
- builder
- Returns:
- fromClause
sqlalchemy.sql.FromClause
Table or clause for the element which is joined.
- fromClause
Notes
Elements are only included in queries via spatial and/or temporal joins when necessary to connect them to other elements in the query, so
regions
andtimespans
cannot be assumed to be notNone
just because an element has a region or timespan.
- abstract sync(record: DimensionRecord, update: bool = False) bool | Dict[str, Any] ¶
Synchronize a record with the database, inserting it only if it does not exist and comparing values if it does.
- Parameters:
- Returns:
- Raises:
- DatabaseConflictError
Raised if the record exists in the database (according to primary key lookup) but is inconsistent with the given one.
- TypeError
Raised if the element does not support record synchronization.
- sqlalchemy.exc.IntegrityError
Raised if one or more records violate database integrity constraints.