ClickHouse/docs/zh/sql-reference/aggregate-functions/reference/groupbitmapor.md
2021-03-25 17:09:19 +08:00

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groupBitmapOr

Calculations the OR of a bitmap column, return cardinality of type UInt64, if add suffix -State, then return bitmap object. This is equivalent to groupBitmapMerge.

groupBitmapOr(expr)

Parameters

expr An expression that results in AggregateFunction(groupBitmap, UInt*) type.

Return value

Value of the UInt64 type.

Example

DROP TABLE IF EXISTS bitmap_column_expr_test2;
CREATE TABLE bitmap_column_expr_test2
(
    tag_id String,
    z AggregateFunction(groupBitmap, UInt32)
)
ENGINE = MergeTree
ORDER BY tag_id;

INSERT INTO bitmap_column_expr_test2 VALUES ('tag1', bitmapBuild(cast([1,2,3,4,5,6,7,8,9,10] as Array(UInt32))));
INSERT INTO bitmap_column_expr_test2 VALUES ('tag2', bitmapBuild(cast([6,7,8,9,10,11,12,13,14,15] as Array(UInt32))));
INSERT INTO bitmap_column_expr_test2 VALUES ('tag3', bitmapBuild(cast([2,4,6,8,10,12] as Array(UInt32))));

SELECT groupBitmapOr(z) FROM bitmap_column_expr_test2 WHERE like(tag_id, 'tag%');
┌─groupBitmapOr(z)─┐
             15   
└──────────────────┘

SELECT arraySort(bitmapToArray(groupBitmapOrState(z))) FROM bitmap_column_expr_test2 WHERE like(tag_id, 'tag%');
┌─arraySort(bitmapToArray(groupBitmapOrState(z)))─┐
 [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]           
└─────────────────────────────────────────────────┘