What does it do? This statement either deletes a line itab_line or multiple lines itab_lines, which can be specified using a table key or a table index, or it deletes adjacent duplicate lines duplicates. System Fields sy-subrcMeaning 0At least one line was deleted. 4No lines were deleted, since no appropriate line was found when deleting using a table key or when specifying a logical expression, the index specified when deleting using a table index was greater than the current number of lines, or no duplicate adjacent lines were found. The system field sy-tabix is not set.
Latest notes:
Deleting lines of internal tables using DELETE does not usually release any memory in the internal table. Statements such as CLEAR or FREE must be used to release this memory.
An internal table in which all lines have been deleted with DELETE is empty and the relational expression IS INITIAL is true. Nevertheless, the internal table usually still occupies memory and therefore is not in the same state as an initial table after its declaration. BEGIN_SECTION SAP_INTERNAL_HINT Only if all lines of an internal table are deleted using a WHERE condition, internally a CLEAR is executed after collecting the lines for deletion and the respective memory is released. But this should not be used as a feature to clear internal tables. END_SECTION SAP_INTERNAL_HINT
When deleting lines in an internal table, costs are incurred for updating all existing table keys and table indexes. The primary key and all unique secondary keys are updated directly, whereas non-unique secondary keys are only updated if the lines to be deleted are contained within an updated part of a relevant index (lazy update). When deleting a line from a standard table and the line is found using a secondary key, the primary table index in particular must be updated, which usually requires a linear search.
