Does anyone know what the following events from the query_events table are in detail? Is there anywhere in the documentation that explains them fully? Which ones are bad, good, ok
Code: Select all
vertica=> select distinct event_type, event_description from query_events order by 1, 2;
event_type | event_description
--------------------------------------+-------------------------------------------------------------------------------------------------------------
DELETE WITH NON OPTIMIZED PROJECTION | Deleting rows in a projection required the slow path
GROUPBY PUSHDOWN | The optimizer pushed GroupBy past a Join
GROUP_BY_PREPASS_FALLBACK | In-memory prepass disabled due to ineffectiveness.
GROUP_BY_SPILLED | GROUP BY key set did not fit in memory, using external sort grouping.
MEMORY LIMIT HIT | The optimizer used all of its allocated memory while planning
MERGE_CONVERTED_TO_UNION | Merge converted to union, followed by sort.
NO GROUPBY PUSHDOWN | The optimizer couldn't push GroupBy past Join
NO HISTOGRAM | The optimizer encountered a predicate on a column for which it does not have a histogram
PARTITIONS_ELIMINATED | Some storage containers will not be processed because they contain no relevant data.
PREDICATE OUTSIDE HISTOGRAM | The optimizer encountered a predicate that was false for the entire histogram.
RESEGMENTED_MANY_ROWS | Many rows were resegmented during plan execution.
RLE_OVERRIDDEN | Compressed execution will not be used on some columns, because the average run counts are not large enough.
SEQUENCE CACHE REFILLED | Session Cache for a sequence has been used up. Taking a GLOBAL CATALOG X Lock to replenish the cache.
SIP_FALLBACK | Sideways information passing filter disabled due to ineffectiveness.
SMALL_MERGE_REPLACED | Small StorageMerge replaced with StorageUnion for efficiency
TRANSITIVE PREDICATE | The optimizer created a transitive predicate due to a join condition
WOS_SPILL | WOS Full; spilling to a new ROS container
(17 rows)