Bug #15089 | BLOB data should not remain in memory | ||
---|---|---|---|
Submitted: | 21 Nov 2005 4:24 | Modified: | 20 May 2009 7:32 |
Reporter: | Gili | Email Updates: | |
Status: | Verified | Impact on me: | |
Category: | MySQL Server | Severity: | S2 (Serious) |
Version: | 3.1.10, 4.1, 5.0, 5.1, 6.0 bzr | OS: | Any (Linux, Windows XP sp2) |
Assigned to: | CPU Architecture: | Any | |
Tags: | affects_connectors |
[21 Nov 2005 4:24]
Gili
[21 Nov 2005 21:34]
Mark Matthews
This is a limitation with the server, neither the MySQL network protocol, nor the server itself allow a client to retrieve a BLOB piecemeal in an _efficient_ fashion. (The JDBC driver can do this if "emulateLocators" is set to true in the configuration properties, but this still requires the _server_ to load the ENTIRE LOB for each request of a "chunk" of it from the input stream returned to the application by the JDBC driver).
[20 May 2009 7:38]
Sveta Smirnova
This partially fixed in patch for bug #38002.
[18 Nov 2009 9:19]
Sveta Smirnova
Bug #48085 was marked as duplicate of this one.
[21 Apr 2010 6:46]
Sveta Smirnova
Bug #47623 was marked as duplicate of this one.
[26 Nov 2011 19:05]
Gili T.
Mark and Sveta, What is the updated status now that bug #38002 was fixed? Does the server still load the entire LOB each time a chunk of it is requested by the JDBC driver?
[26 Nov 2011 20:37]
Mark Matthews
That fix is orthogonal to the issue. MySQL can still only load entire blobs to satisfy requests for portions of them. It is a limitation imposed by the storage engine API, requests for partial column values are not supported.
[26 Nov 2011 21:07]
Gili T.
Okay. I filed RFE #63441