Distributed Exchange types The following exchange types indicate the layout of the data when they are exchanged between nodes in a distributed plan. HASH –The exchange distributes data to multiple destinations
Join method – The method (e.g., hash, sort-merge, etc.) used to join tables with each other. Join type – The type of join (e.g., outer, anti, semi, etc.). Join order – The order in which the tables are joined to each other. Partition pruning – Are...
For example, if a hash aggregate operator is used in the first step of a query plan, full data of downstream operators is required to create a hash table for an aggregate operation. For common queries with filter conditions, data is calculated and returned in real time. In this scenario, ...
gaussdb=# CREATE TABLE chinamap ( id integer, pid integer, name text ) DISTRIBUTE BY hash(id); -- Plan collected by plan_table. gaussdb=# EXPLAIN PLAN SET statement_id = 'cte can not be push down' FOR WITH RECURSIVE rq AS ( SELECT id, name FROM chinamap WHERE id = 11 UNION ALL...
Fast file hash? Faster Deep Cloning Faster way to get folder size? Faster way to Read XML in C#.Net Fastest method to convert bitmap object to byte array Fastest way to do string comparisons? Hashset.Contains? Fastest way to iterate through an IEnumerable<T> Fastest way to read a hug...
func (e *HashAggExec) Next(ctx context.Context, chk *chunk.Chunk) error { if e.runtimeStat != nil { start := time.Now() defer e.runtimeStat.Record(time.Now().Sub(start), chk.NumRows()) Contributor crazycs520 Oct 11, 2018 Defer function input parameter will be calculated...
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1) First, we lock a distinct TDUSER."pseudo table" for read on a RowHash to prevent global deadlock for TDUSER.employee. 2) Next, we lock TDUSER.employee for read. 3) We do an all-AMPs RETRIEVE step from TDUSER.employee by way of an all-rows scan with no residual conditions ...
• The Range of Character is -128 to 127 Identifiers The Identifiers are those which are used for giving a name to a variables, arrays, functions, classes, structures, namespaces and so on, like a b etc these are used for naming a variable. When we dec...
There are two types of data types in Java: Primitive data types: The primitive data types include boolean, char, byte, short, int, long, float and double. Non-primitive data types: The non-primitive data types include enum, Classes, Interfaces, and Arrays....