Mirroring 101

Caché mirroring is a reliable, inexpensive, and easy to implement high availability and disaster recovery solution for Caché and Ensemble-based applications. Mirroring provides automatic failover under a broad range of planned and unplanned outage scenarios, with application recovery time typically limited to seconds. Logical data replication eliminates storage as a single point of failure and a source of data corruption. Upgrades can be executed with little or no downtime.

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Article
Tony Pepper · May 25, 2016 5m read
Random Read IO Storage Performance Tool

Purpose

This tool is used to generate random read Input/Output (IO) from within the database. The goal of this tool is to drive as many jobs as possible to achieve target IOPS and ensure acceptable disk response times are sustained. Results gathered from the IO tests will vary from configuration to configuration based on the IO sub-system. Before running these tests ensure corresponding operating system and storage level monitoring are configured to capture IO performance metrics for later analysis.

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Caché Monitor is a database\sql tool primarily for InterSystems Caché but can also connect to MS SQL Server, MS Access and more databases. Within Caché Monitors Server Navigator you see all available Namespaces on your Caché Servers. No need to know the name of the Namespace, no need to configure many many JDBC Connections by hand. Just click on the namespace and see all objects like tables, views, classes and more...

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We have a new requirement being push down by our Data Security to no longer use Local SQL Accounts to access our Databases. So they asked me to create a Service Account that is on the Domain for our connections to each database.

I tried just changing my JDBC connection to using this Service Account and Password but I am not having any luck trying to connect to the database.

" Connection failed.
Login failed for user 'osumc\CPD.Intr.Service'. ClientConnectionId:ade97239-c1c8-4ed1-8230-d274edb2e731 "

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The object and relational data models of the Caché database support three types of indexes, which are standard, bitmap, and bitslice. In addition to these three native types, developers can declare their own custom types of indexes and use them in any classes since version 2013.1. For example, iFind text indexes use that mechanism.

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Question
Thembelani Mlalazi · Mar 12, 2019
String to date

I am trying to convert a string to date but can not get it to work I have  function that I would like to take in a date string and covert it to date object

here is the ezample so far can not get it to work any help appreciated 

 

set p="12/03/2019"
 
w $System.SQL.TODATE(p,"YYYY-MM-DD")
 
<ILLEGAL VALUE>todate+32^%qarfunc

if I try this still get the wrong value returned

set p="12/03/2019" 
w $ZDATE(p,3)
1841-01-12

 

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to dismount/mount a database, use Dismount() and Mount() methods in SYS.Database class available in %SYS namespace.
NB: the database ID is its Directory

You'll find  some examples of how to dismount/mount and check if a database is mounted (Mounted=1) or not (Mounted=0), and quickly see all the attributes of a database (via zwrite)

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This text is a continuation of my article where I explained the structure a Caché database. In this article, I described the types of blocks, connections between them and their relation to globals. The article was purely theoretical. I made a project that helps visualize the block tree - and this article will explain how it works in great detail.

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Article
Jorma Sinnamo · Nov 8, 2016 4m read
Returning Disk Space to File Systems

This is the first article in a series discussing how to regain disk space from Caché databases at the operating system level. This introductory article discusses Caché database growth and gives an overview of various methods you can use to return unused disk space that is allocated to database files back to the file system. But before we talk about returning space to the file system, let’s first review how does it get allocated in the first place.

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We have noticed in the course of the last 18 days our CACHE.dat has grown by 20 GB. Is there a way we can break down the data in CACHE.dat to see what could be growing in size?

Let me state it another way.....Is there a way to see what space an Operation/Service/Process is taking up within a certain Production?

Thanks

Scott Roth

The Ohio State University Wexner Medical Center

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I am looking for a database management tool I would have expected to find something like on the SMP website

 

Aim

show current database usage (ie size allocation) by database then table etc and allow continued drill down,

show information as a table, so can then sort by size to find the biggest item easily

also show it graphically

 

And then have ability to track and trend growth in size over time

identify a normal growth pattern

alert if variation (higher or lower) from normal based on recent trend

 

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Mirror Outage Procedures

Caché mirroring is a reliable, inexpensive and easy to implement high availability and disaster recovery solution for Caché and Ensemble-based applications. This article provides an overview of recommended procedures for dealing with a variety of planned and unplanned mirror outage scenarios.

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Introduction

In the first article in this series, we’ll take a look at the entity–attribute–value (EAV) model in relational databases to see how it’s used and what it’s good for. Then we'll compare the EAV model concepts to globals.

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Greetings,

I am working on the first of many triggers which will have identical code upon row insertion or update of a single column.  According to the document I should be able to define a multiple-event trigger using Cache SQL/DDL.

Here is a link to the current CREATE TRIGGER documentation.  Within the description section is the following paragraph:

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