Package org.apache.druid.java.util.common.granularity

Class Granularities

java.lang.Object

org.apache.druid.java.util.common.granularity.Granularities

public class Granularities
extends Object

This class was created b/c sometimes static initializers of a class that use a subclass can deadlock. See: #2979, #3979

Field Summary

Fields

Modifier and Type	Field	Description
static final Granularity	ALL
static final Granularity	DAY
static final Granularity	EIGHT_HOUR
static final Granularity	FIFTEEN_MINUTE
static final Granularity	FIVE_MINUTE
static final String	GRANULARITY_VIRTUAL_COLUMN_NAME
static final Granularity	HOUR
static final Granularity	MINUTE
static final Granularity	MONTH
static final Granularity	NONE
static final Granularity	QUARTER
static final Granularity	SECOND
static final Granularity	SIX_HOUR
static final Granularity	TEN_MINUTE
static final Granularity	THIRTY_MINUTE
static final Granularity	WEEK
static final Granularity	YEAR

Constructor Summary

Constructors

Constructor	Description
Granularities()

Method Summary

Modifier and Type	Method	Description
static CursorBuildSpec	decorateCursorBuildSpec(Query<?> query, CursorBuildSpec buildSpec)	Decorates CursorBuildSpec with a grouping column and virtual column equivalent to the Granularity for a Query, if that query has granularity other than ALL.
static Granularity	fromVirtualColumn(VirtualColumn virtualColumn)	Converts a virtual column with a single input time column into a Granularity if it is a TimestampFloorExprMacro.TimestampFloorExpr.
static Granularity	nullToAll(Granularity granularity)
static ExpressionVirtualColumn	toVirtualColumn(Granularity granularity, String virtualColumnName)	Translates a Granularity to a ExpressionVirtualColumn on ColumnHolder.TIME_COLUMN_NAME of the equivalent grouping column.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

SECOND

public static final Granularity SECOND

MINUTE

public static final Granularity MINUTE

FIVE_MINUTE

public static final Granularity FIVE_MINUTE

TEN_MINUTE

public static final Granularity TEN_MINUTE

FIFTEEN_MINUTE

public static final Granularity FIFTEEN_MINUTE

THIRTY_MINUTE

public static final Granularity THIRTY_MINUTE

HOUR

public static final Granularity HOUR

SIX_HOUR

public static final Granularity SIX_HOUR

EIGHT_HOUR

public static final Granularity EIGHT_HOUR

DAY

public static final Granularity DAY

WEEK

public static final Granularity WEEK

MONTH

public static final Granularity MONTH

QUARTER

public static final Granularity QUARTER

YEAR

public static final Granularity YEAR

ALL

public static final Granularity ALL

NONE

public static final Granularity NONE

GRANULARITY_VIRTUAL_COLUMN_NAME

public static final String GRANULARITY_VIRTUAL_COLUMN_NAME

See Also:

• Constant Field Values

Constructor Details

Granularities

public Granularities()

Method Details

nullToAll

public static Granularity nullToAll(Granularity granularity)

decorateCursorBuildSpec

public static CursorBuildSpec decorateCursorBuildSpec(Query<?> query,
 CursorBuildSpec buildSpec)

Decorates CursorBuildSpec with a grouping column and virtual column equivalent to the Granularity for a Query, if that query has granularity other than ALL. If the query has 'ALL' granularity, the CursorBuildSpec will be returned as is. The reason for this is that a query with a granularity that is not 'ALL' is effectively an additional grouping on TIME_FLOOR(__time, granularity), so by adding this to the CursorBuildSpec allows a CursorHolder to potentially specialize any Cursor or VectorCursor it provides by using pre-aggregated data at the closest matching granularity if available.

See Also:

• for how Granularity is translated into a VirtualColumn

toVirtualColumn

@Nullable
public static ExpressionVirtualColumn toVirtualColumn(Granularity granularity,
 String virtualColumnName)

Translates a Granularity to a ExpressionVirtualColumn on ColumnHolder.TIME_COLUMN_NAME of the equivalent grouping column.

• If granularity is ALL, this method returns null since we are not grouping on time.
• If granularity is a PeriodGranularity, we'd map it to TimestampFloorExprMacro.TimestampFloorExpr.
• If granularity is NONE, or any other kind of granularity (duration, period with non-utc timezone or origin) this method returns a virtual column with IdentifierExpr specifying ColumnHolder.TIME_COLUMN_NAME directly.

fromVirtualColumn

@Nullable
public static Granularity fromVirtualColumn(VirtualColumn virtualColumn)

Converts a virtual column with a single input time column into a Granularity if it is a TimestampFloorExprMacro.TimestampFloorExpr.

IMPORTANT - this method DOES NOT VERIFY that the virtual column has a single input that is a time column (ColumnHolder.TIME_COLUMN_NAME or equivalent projection time column as defined by AggregateProjectionSchema.getTimeColumnName()). Callers must verify this externally before calling this method by examining VirtualColumn.requiredColumns().

This method also does not handle other time expressions, or if the virtual column is just an identifier for a time column