Refined comment. [#CLICKHOUSE-2]

This commit is contained in:
Vitaliy Lyudvichenko 2018-03-12 22:02:54 +03:00
parent bfd11656d1
commit 0b82551829

View File

@ -105,7 +105,8 @@ BlockIO InterpreterInsertQuery::execute()
out = std::make_shared<AddingDefaultBlockOutputStream>( out = std::make_shared<AddingDefaultBlockOutputStream>(
out, getSampleBlock(query, table), required_columns, table->column_defaults, context); out, getSampleBlock(query, table), required_columns, table->column_defaults, context);
/// Do not squash blocks if it is a sync INSERT into Distributed /// Do not squash blocks if it is a sync INSERT into Distributed, since it lead to double bufferization on client and server side.
/// Client-side bufferization might cause excessive timeouts (especially in case of big blocks).
if (!(context.getSettingsRef().insert_distributed_sync && table->getName() == "Distributed")) if (!(context.getSettingsRef().insert_distributed_sync && table->getName() == "Distributed"))
{ {
out = std::make_shared<SquashingBlockOutputStream>( out = std::make_shared<SquashingBlockOutputStream>(