These terms are used in EXPLAIN phrases.
| Phrase | Explanation |
|---|---|
| by way of external metadata ... | |
| This NOS-specific phrase is in an all-AMP step that accesses one NOS table from the primary cluster or compute cluster. Each AMP reads its assigned objects based on previously read metadata, transforms the object data into relational rows, and may spool the data in preparation of a later join or aggregation. | |
| which is binpacked and redistributed by size ... | |
| This phrase is NOS-specific and appears in the second single-AMP metadata step before the all-AMP access step that accesses the row of a foreign table. A binpacking algorithm reads the filename and sizes from the previous single-AMP step and divides the objects across all AMPs. | |
| We materialize NOS or Object File System table name ... | |
| This phrase is in a primary cluster step that sends instructions to a compute cluster to materialize table headers for either foreign tables or Object File System tables in preparation for reading the object storage tables. | |
| redistributed randomly to all AMPs in COMPUTE map-name … | |
| This phrase is used when a table or spool file is shipped from either the primary cluster to the compute cluster, or the compute cluster to the primary cluster. | |