tdigest_merge()

Merges tdigest results (scalar version of the aggregate version tdigest_merge()).

Read more about the underlying algorithm (T-Digest) and the estimated error here.

Syntax

merge_tdigests( Expr1, Expr2, ...)

tdigest_merge( Expr1, Expr2, ...) - An alias.

Arguments

  • Columns that have the tdigest values to be merged.

Returns

The result for merging the columns *Expr1*, *Expr2*, ... *ExprN* to one tdigest.

Examples

range x from 1 to 10 step 1 
| extend y = x + 10
| summarize tdigestX = tdigest(x), tdigestY = tdigest(y)
| project merged = tdigest_merge(tdigestX, tdigestY)
| project percentile_tdigest(merged, 100, typeof(long))
percentile_tdigest_merged
20