BigQuery use conditions to create a table from other tables (manage big number of columns)
问题 I am facing an issue related to a project of mine. Here is the summary of what i would like to do : I have a big daily file (100 Go) with the following extract (no header) : ID_A|segment_1 ID_A|segment_2 ID_B|segment_2 ID_B|segment_3 ID_B|segment_4 ID_B|segment_5 ID_C|segment_1 ID_D|segment_2 ID_D|segment_4 Every ID (from A to D) can be linked to one or multiple segments (from 1 to 5). I would like to process this file in order to have the following result (the result file contains a header)