Understanding SQL Loader

SQL Loader is a tool for inserting third-party system data in various format types, such as CSV, TXT, or any delimited format. The structure of the data is defined by the associated control file controlling the mapping. SQL Loader is a user (client) process defined by the extraction of data rows in the first phase, followed by loading tuples. The loading process can be done conventionally (the insert statements are generated with regard to the UNDO and REDO data logs) or via a direct path (in this case, the buffer cache is bypassed, and data is loaded directly into the data files in a block format). No UNDO data log content is generated. The High Water Mark (HWM) pointer is shifted to point to another location after processing, making new blocks with data accessible to the table structure. The HWM pointer references the last associated block of the particular table. Thus, the direct path type is significantly faster and requires less storage (even REDO logging...