Release Notes

Xeround Cloud Database – Product Release Information

Release Date: February 6, 2013

What’s New | Previous Versions | Compatibility | Additional Topics |

Customer Support: For more information or support, please visit support.xeround.com or email us at support@xeround.com

Introduction:

This document contains the release notes for Xeround version 3.2.4

Your feedback is important to us; please help us improve Xeround Cloud Database by reporting any issues, change requests, or sharing any feedback you may have, by emailing support@xeround.com

Xeround provides a distributed storage engine that’s used by a distributed setup of MySQL front-ends. Therefore, some of MySQL’s features are not applicable or not relevant in Xeround, such as SQL Replication Statements and Partition directives.

What’s New?

Added support for Full Text Search via Full Text Index:
MySQL version upgraded to 5.5.20
Please see MySQL 5.5 Release notes and their recommendations for upgrading from MySQL 5.1 (Xeround’s previous version) to MySQL 5.5.

Note that any changes regarding ‘replication’, ‘partitioning’ and specific storage engines, such as INNODB and MYISAM are not relevant to Xeround Cloud Database- as high availability, scalability and other advanced capabilities are automatically handled by the service.
Major performance improvements have been achieved
Xeround BASIC edition now supports restore-from-backup capability
Static tables can be cached in the frontend layer by adding the keyword XEROUND_CACHE to the create table statement. For example:
create table examples (pk int primary key, a int) XEROUND_CACHE;
Btree indexes can be cached in memory for further performance improvement by naming the index with the prefix “xyz_xeround_cached”. For example –
Create index xyz_xeround_cached_ix1 on examples(a)

Previous Versions’ Updates:

Oct, 2012: Introduced SSL support: SSL connections to the database instance are supported for the following Ciphers:

DES-CBC3-SHA
RC4-SHA
RC4-MD5
DES-CBC-SHA
AES128-SHA
AES256-SHA

IP Based Access Control support
ALTER Table coverage is enhanced and supports now column type conversion for:

INTEGER to/from STRING
INTEGER to/from FLOAT, DOUBLE
STRING to FLOAT, DOUBLE

The following type conversions are not yet supported:

FLOAT, DOUBLE to STRING
Binary types
Date&time related types
Alter table … modify column add / remove / change auto_increment is currently not supported.

Compatibility:

Xeround current release is compatible with MySQL v5.5.20 feature set (with some exceptions as described below).
You can access Xeround Cloud Database at https://cloud.xeround.com. For optimal experience, you’ll need to use one of the following fully supported browsers:
- Chrome 6.0
- Internet Explorer 6.0+
- Firefox 3.6

SQL and MySQL Compatibility:

Xeround is targeted to be SQL compliant with MySQL, with regards to Data Types, Functions and Operators and SQL Statements.

In spite of the above, the following SQL functionality is NOT SUPPORTED in the current release:

ALTER TABLE {ADD|DROP} PRIMARY KEY. A table’s primary key constraint can only be defined while creating a table and as a part of the CREATE TABLE DDL.
INSERT IGNORE, INSERT …ON DUPLICATE KEY UPDATE & REPLACE – these statements are supported for a single operation transaction, or when the duplicate values are both in the same transaction. In bulk operations/transactions, a uniqueness constraint violation might fail the entire transaction.
Log files
Event
Save points
The following Grant options : MAX_QUERIES_PER_HOUR, MAX_UPDATES_PER_HOUR, MAX_CONNECTIONS_PER_HOUR and MAX_USER_CONNECTIONS
Spatial extensions: data types, indexes and functions
The following indexes-related functionality:
1. RTREE
2. Show index collation & cardinality
LOCK statements

In addition, the following limitations apply:

Hash index has a limited cardinality of 1000 per value – for higher cardinality please use Btree index
Maximal transaction size should not exceed 100M
Due to schema distribution process among the various nodes, it is highly recommended to wait at least 30 seconds after performing DDL operations before referring to its results
Foreign Key constraints are supported but not enforced
Host based privileges are not enforced – it is highly recommended that you do not use them as these may result in unexpected behavior
AUTO_INCREMENT columns support only positive integer values
Cascading triggers are supported but are not included in the scope of the original transaction
LOAD DATA INFILE statements are supported only when executed with the LOCAL keyword

Please also be aware of the following topics:

Xeround uses Optimistic Concurrency Control in implementing ACID transactions. Therefore applications should deal with failures when committing changes
When using table scan operations, the order of the returned data is not guaranteed. To assure the order of the returned data, please use the ORDER BY clause
INSERT INTO MYTABLE (PK) SELECT MYTABLE.PK + 5 FROM MYTABLE WHERE PK > 100;) may result in unexpected behavior as some rows might be inserted more than once
INSERT INTO…ON DUPLICATE KEY UPDATE – AUTO_INCREMENT on the primary key will increment even if INSERT finds a duplicate key and an UPDATE was executed.
- Xeround FREE and BASIC editions have some safeguard on schema size. On the rare occasion an error message regarding schema size reached pops – please contact support.
Not supported charsets:
- utf8mb4*
- swe7_swedish_ci
- swe7_bin
- armscii8_general_ci
- armscii8_bin
- keybcs2_general_ci
- keybcs2_bin
- geostd8_general_ci
- geostd8_bin
Sinhala language for collation is not supported