kgyrtkirk commented on code in PR #14848: URL: https://github.com/apache/druid/pull/14848#discussion_r1301478602
########## docs/querying/sql-aggregations.md: ########## @@ -86,16 +86,11 @@ In the aggregation functions supported by Druid, only `COUNT`, `ARRAY_AGG`, and |`STDDEV_POP(expr)`|Computes standard deviation population of `expr`. See [stats extension](../development/extensions-core/stats.md) documentation for additional details.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| |`STDDEV_SAMP(expr)`|Computes standard deviation sample of `expr`. See [stats extension](../development/extensions-core/stats.md) documentation for additional details.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| |`STDDEV(expr)`|Computes standard deviation sample of `expr`. See [stats extension](../development/extensions-core/stats.md) documentation for additional details.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| -|`EARLIEST(expr)`|Returns the earliest value of `expr`, which must be numeric. If `expr` comes from a relation with a timestamp column (like `__time` in a Druid datasource), the "earliest" is taken from the row with the overall earliest non-null value of the timestamp column. If the earliest non-null value of the timestamp column appears in multiple rows, the `expr` may be taken from any of those rows. If `expr` does not come from a relation with a timestamp, then it is simply the first value encountered.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| -|`EARLIEST(expr, maxBytesPerString)`|Like `EARLIEST(expr)`, but for strings. The `maxBytesPerString` parameter determines how much aggregation space to allocate per string. Strings longer than this limit are truncated. This parameter should be set as low as possible, since high values will lead to wasted memory.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `''`| -|`EARLIEST_BY(expr, timestampExpr)`|Returns the earliest value of `expr`, which must be numeric. The earliest value of `expr` is taken from the row with the overall earliest non-null value of `timestampExpr`. If the earliest non-null value of `timestampExpr` appears in multiple rows, the `expr` may be taken from any of those rows.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| -|`EARLIEST_BY(expr, timestampExpr, maxBytesPerString)`| Like `EARLIEST_BY(expr, timestampExpr)`, but for strings. The `maxBytesPerString` parameter determines how much aggregation space to allocate per string. Strings longer than this limit are truncated. This parameter should be set as low as possible, since high values will lead to wasted memory.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `''`| -|`LATEST(expr)`|Returns the latest value of `expr`, which must be numeric. The `expr` must come from a relation with a timestamp column (like `__time` in a Druid datasource) and the "latest" is taken from the row with the overall latest non-null value of the timestamp column. If the latest non-null value of the timestamp column appears in multiple rows, the `expr` may be taken from any of those rows. |`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| -|`LATEST(expr, maxBytesPerString)`|Like `LATEST(expr)`, but for strings. The `maxBytesPerString` parameter determines how much aggregation space to allocate per string. Strings longer than this limit are truncated. This parameter should be set as low as possible, since high values will lead to wasted memory.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `''`| -|`LATEST_BY(expr, timestampExpr)`|Returns the latest value of `expr`, which must be numeric. The latest value of `expr` is taken from the row with the overall latest non-null value of `timestampExpr`. If the overall latest non-null value of `timestampExpr` appears in multiple rows, the `expr` may be taken from any of those rows.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| -|`LATEST_BY(expr, timestampExpr, maxBytesPerString)`|Like `LATEST_BY(expr, timestampExpr)`, but for strings. The `maxBytesPerString` parameter determines how much aggregation space to allocate per string. Strings longer than this limit are truncated. This parameter should be set as low as possible, since high values will lead to wasted memory.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `''`| -|`ANY_VALUE(expr)`|Returns any value of `expr` including null. `expr` must be numeric. This aggregator can simplify and optimize the performance by returning the first encountered value (including null)|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| -|`ANY_VALUE(expr, maxBytesPerString)`|Like `ANY_VALUE(expr)`, but for strings. The `maxBytesPerString` parameter determines how much aggregation space to allocate per string. Strings longer than this limit are truncated. This parameter should be set as low as possible, since high values will lead to wasted memory.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `''`| +|`EARLIEST(expr, [maxBytesPerString])`|Returns the earliest value of `expr`.<br />If `expr` comes from a relation with a timestamp column (like `__time` in a Druid datasource), the "earliest" is taken from the row with the overall earliest non-null value of the timestamp column.<br />If the earliest non-null value of the timestamp column appears in multiple rows, the `expr` may be taken from any of those rows. If `expr` does not come from a relation with a timestamp, then it is simply the first value encountered.<br /><br />If `expr` is a string or complex type `maxBytesPerString` amount of space is allocated for the aggregation. Strings longer than this limit are truncated. The `maxBytesPerString` parameter should be set as low as possible, since high values will lead to wasted memory.<br/>If `maxBytesPerString`is omitted; it defaults to `1024`. |`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0` or `''` (depending on the type of `expr`)| Review Comment: I was thinking to also replace `maxBytesPerString` everywhere in the main codebase - but it seems like this `maxBytesPerString` may also appear in the `native` api...so decided against that: https://druid.apache.org/docs/latest/querying/aggregations/ I believe a change like that may cause some troubles - so I wonder which path should we take: * (A) rename those as well * I would be worried that by doing this would cause some confusion to users / native api client using the system * (B) leave them alone * current state of the PR * (C) undo this rename * so the native api is in line with the docs regarding this * (X) something else? :D -- This is an automated message from the Apache Git Service. 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