thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-09-21 01:00:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

Added comments.

Browse Source
This commit is contained in:
Vladimir Chebotarev 2020-07-13 07:15:37 +03:00
parent ea8fae8142
commit 820e95ae3c
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/IO/SeekAvoidingReadBuffer.h
View File

@ -6,10 +6,15 @@
namespace DB
{
/// `SeekAvoidingReadBuffer` prefers sequential reads over seeks within specified window.
/// It is useful in network and spinning disk storage media when seek is relatively expensive
/// operation.
/// See also: `merge_tree_min_rows_for_seek`.
class SeekAvoidingReadBuffer : public ReadBufferFromFileBase
{
std::unique_ptr<ReadBufferFromFileBase> nested;
UInt64 min_bytes_for_seek;
UInt64 min_bytes_for_seek; /// Minimum positive seek offset which shall be executed using seek operation.
public:
SeekAvoidingReadBuffer(std::unique_ptr<ReadBufferFromFileBase> nested_, UInt64 min_bytes_for_seek_);