Sets the period for a real clock timer of the [query profiler](../performance/sampling_query_profiler.md). Real clock timer counts wall-clock time.
Sets the period for a real clock timer of the [query profiler](../../operations/performance/sampling_query_profiler.md). Real clock timer counts wall-clock time.
-`startdate` — The first time value to compare. [Date](../../data_types/date.md) or [DateTime](../../data_types/datetime.md).
-`enddate` — The second time value to compare. [Date](../../data_types/date.md) or [DateTime](../../data_types/datetime.md).
-`timezone` — Optional parameter. If specified, it is applied to both `startdate` and `enddate`. If not specified, timezones of `startdate` and `enddate` are used. If they are not the same, the result is unspecified.[Time Zone](../../data_types/datetime.md#time-zones).
-`timezone` — Optional parameter. If specified, it is applied to both `startdate` and `enddate`. If not specified, timezones of `startdate` and `enddate` are used. If they are not the same, the result is unspecified.
The same as [position](#position) but returns `Array` of positions (in bytes) of the found corresponding substrings in the string. Positions are indexed starting from 1.
The same as [position](string_search_functions.md#position) but returns `Array` of positions (in bytes) of the found corresponding substrings in the string. Positions are indexed starting from 1.
The search is performed on sequences of bytes without respect to string encoding and collation.
-[Использование MySQL как источника данных для внешнего словаря](../dicts/external_dicts_dict_sources.md#dicts-external_dicts_dict_sources-mysql)
-[Использование MySQL как источника данных для внешнего словаря](../../query_language/dicts/external_dicts_dict_sources.md#dicts-external_dicts_dict_sources-mysql)