In this article Barry Mavin, CEO and Chief Software Architect for Recital, details how to use the Recital Database Server with Visual FoxPro.
We are pleased to announce the release of Recital 10.0.3.
Here is a brief list of features and functionality that you will find in the 10.0.3 release.
- New Commands:
- SET TMPNAMPATH ON|OFF
- REMOVE TABLE - New Functions:
- CURSORGETPROP()
- CURSORSETPROP()
- CURVAL()
- GETFLDSTATE()
- OLDVAL()
- TABLEREVERT()
- TABLEUPDATE()
- SETFLDSTATE() - Enhanced Functions:
- TMPNAM() - additional parameter to specify the return of basename only
- MAILATTACH() - parameter changed from array to filename to allow directory and file extension to be specified - Enhancements:
- DO level increased from 32 to 64. - Fixes:
- Delay exiting Recital after SYS(3) or SYS(2015)
- SET SOFTSEEK issue when search key above first record in index
- Compilation error with REPLACE command after UDF call
- FETCH INTO memvars error
- END TRANSACTION at command prompt error
- ROLLBACK locking error
- Linux ODBC Driver undefined symbol error
- RELEASE variable with same name as variable in calling program issue
- SQLCODE() issue on non-gateway data access
- Issuing two SQLEXEC() calls error
- LASTSEQNO() in workareas > 1 error
- SET RELATION to detail table in workarea 1 issue
- LIST STATUS on empty table delay
- SET AUTOCATALOG alias entries error
- ADD OBJECT in DEFINE CLASS error
- DEACTIVATE WINDOW error
- SORT error
- Other reported bugs
When stress testing our loadbalancer, i was unable to get more than 20 reliable ssh connections. The following error would be reported.
ssh_exchange_identification: Connection closed by remote host
The resolution for this is quite simple.
Edit the /etc/ssh/sshd_config file and increase the MaxStartups. On my server i set this to 200.
Edit /etc/sysctrl.conf and add the following line:
net.core.netdev_max_backlog = 3000
Then apply this change:
# sysctl -p
If you want details about how storage devices are performing on Redhat/Centos/Fedora use the vmstat and iostat commands.
After installing Centos 5.3 the iostat command is not available. To install it use yum:
# yum install sysstat
auth sufficient pam_krb5.so try_first_pass
auth sufficient pam_unix.so shadow nullok try_first_pass
account required pam_unix.so broken_shadow
account [default=bad success=ok user_unknown=ignore] pam_krb5.so
Recital provides the following additional benefits:
- Easy to Install and Deploy - Users can set up Recital in minutes enabling organizations to deliver new applications faster than other databases.
- Easy to Administer - Recital is a low administration database that eliminates the need for highly trained, skilled, and costly database administrators to maintain the database.
- High Performance - Superior database performance for the most demanding of OLTP applications. Additionally, Clustered Recital provides 99.999% availability.
- Embeddable Library - Recital Embedded Edition provides in-process data storage engine that delivers all the features of a traditional relational database but in a size which makes it ideally suited for ISVs/VARs who need a small footprint and easy to use toolkit.
- Platform Independence - Recital runs on Linux, Solaris, AIX, HP-UX, Windows, and Mac OS X giving organizations complete flexibility in delivering a solution on the platform of their choice.
USE accounts INDEX on account_no TAG outstanding FOR balance > 0 EXPLAIN SELECT * FROM accounts WHERE balance > 0 Optimized using for condition on tag 'OUTSTANDING'
The Openfiler NAS/SAN Appliance (NSA) is a Storage Management Operating System / NAS Appliance distribution. It is powered by the Linux 2.6 kernel and Open Source applications such as Apache, Samba, LVM2, ext3, Linux NFS and iSCSI Enterprise Target. Openfiler combines these ubiquitous technologies into a small, easy to manage solution fronted by a powerful web-based management interface. Openfiler allows you to build a Network Attached Storage (NAS) and/or Storage Area Network (SAN) appliance, using industry-standard hardware, in less than 10 minutes of installation time.
Building upon the popularity of server virtualization technologies such as VMware, Virtual Iron, and Xen, Openfiler can also be deployed as a virtual machine instance or on a bare metal machine.
This deployment flexibility of Openfiler ensures that storage administrators are able to make the best use of system performance and storage capacity resources when allocating and managing networked storage in a multi-platform environment.
Openfiler is ideally suited for use with High Availability Recital applications as it incorporates:
- Heartbeat cluster manager
- drbd disk replication
- CIFS
- NFS
- Software and hardware RAID
- FTP
- rsync
- HTTP/DAV
- iSCSI
- LVM2
- Multiple NIC bonding for High Availability
- Powerful web-based GUI
System Requirements:
- Minimum memory: 4MB
- Minimum Diskspace: ~20MB
Recital is a dynamic programming language with an embedded high performance database engine particularly well suited for the development and deployment of high transaction throughput applications.
The Recital database engine is not a standalone process with which the application program communicates. Instead, the Recital database is an integral part of any applications developed in Recital.
Recital implements most of the SQL-99 standard for SQL, but also provides lower level navigational data access for performing high transaction throughput. It is the choice of the application developer whether to use SQL, navigational data access, or a combination of both depending upon the type of application being developed.
The Recital database engine, although operating as an embedded database in the user process, multiple users and other background processes may access the same data concurrently. Read accesses are satisfied in parallel. Recital uses automatic record level locking when performing database updates. This provides for a high degree of database concurrency and superior application performance and differentiates the Recital database from other embeddable databases such as sqlite that locks the entire database file during writing.
Key features of the Recital scripting language include:
- High performance database application scripting language
- Modern object-oriented language features
- Easy to learn, easy to use
- Fast, just-in-time compiled
- Loosely-typed
- Garbage collected
- Static arrays, Associative arrays and objects
- Develop desktop or web applications
- Cross-platform support
- Extensive built-in functions
- Superb built-in SQL command integration
- Navigational data access for the most demanding applications
- Scripting language is upward compatible with FoxPRO
Key features of the Recital database include:
- A broad subset of ANSI SQL 99, as well as extensions
- Cross-platform support
- Stored procedures
- Triggers
- Cursors
- Updatable Views
- System Tables
- Query caching
- Sub-SELECTs (i.e. nested SELECTs)
- Embedded database library
- Fault tolerant clustering support
- Chronological data versioning with database timelines
- Optional DES3 encrypted data
- Hot backup
- Client drivers for ODBC, JDBC and .NET