Miguel Pereira on the Web

Originally from Argentina, I relocated to the great state of Texas in early 2001. I am a seasoned IT professional with over a decade of experience working on Windows / ‘nix platforms as a DBA and infrastructure support. By many, considered a “go-to” person when approaching moves to new technology or migration platforms.

I posses over a decade of experience working on Microsoft Server technologies and have covered -and still do- both development and production DBA roles, though my strengths and professional interests are geared towards production & infrastructure planning primarily. I have worked on a wide array of environments, ranging from small startup businesses with minimal IT investment and capitalization where I had oversight of the entire technology footprint, ranging from IP telephony systems, back office communications, and internet / intranet applications and presence; as well as in highly compartmentalized, technology heavy fortune 500 companies where I offered consulting services as a DBA, application roll outs, and configuration management.

Always a team player, I’ve worked on projects with as few as 2 participants all the way up to multi-tiered projects requiring SME’s and POC’s from what seemed to be every IT discipline ever created.

The tedious details

As a DBA, I have 8+ years of experience with Microsoft SQL 2000 and up; having sized and installed hundreds of single instances in both production and development environments supporting both OLTP & OLAP configurations. Experience in T-SQL development and tuning: stored procedures, functions, triggers, constraint selection, various data modeling techniques, as well as adhoc query writing; data mining techniques through SSIS & DTS packages and interoperability with other RDBMS’, including DB2, Informix, mySQL & Oracle. Highly experienced supporting active/passive and mirrored instances for high-availability, along with backup & disaster recovery techniques. Sizing and resource monitoring have always been a very strong facet.

Proficient with Oracle 10g+ database sizing, install & configurations; especially on single-instance, light footprint deployments on Linux environments -primarily Red Hat based OS’. Knowledgeable on PL/SQL query syntax, stored procedures, functions and ETL practices through SQL*Loader; automation of export/import and basic backup & recovery techniques through both RMAN & utilities such as Import / Export aided by Bash shell scripting. Extensive use of OEM to monitor performance and assess tuning results, as well as system resource utilization.

I am very familiar with the Windows Server suite of products from version 2000; I have sized, setup & maintained Active Directory services (i.e. primary / secondary controllers, DHCP, DNS & security objects) and I am intimately familiar with system administration in general of the Windows Server family suite.

I have over 4+ years of experience performing application support along with basic maintenance and monitoring functions on Linux platforms, primarily Red Hat Enterprise and CentOS, on both production and development environments. I am highly proficient in Shell scripting and intimately familiar with the ‘nix security model.

I have 10+ years of experience supporting production-level middleware and application platforms running on Internet Information Services, Apache Web Server, Apache-Tomcat and Oracle (BEA) Web Logic; application side implementations of CA Clarity PPM, CA Business Objects, CA Siteminder, .NET applications, Visual Source Safe, SubVersion, Redmine, Nagios & Sitescope.

I am sure I am forgetting a few more obscure solutions that I’ve had to implement in the past, but here is a brief compilation of some of the most interesting things I’ve had to deal with:

• CA Clarity PPM 12.0.x
  • Platform: RHEL 5.3 64-bit
  • Apache-Tomcat running the application
  • AWS acting as a local reverse-proxy and integration point with CA Siteminder Agent for authentication.
  • Oracle 10g R2 (10.2.0.4) single instances for non-production & a 2-node RAC for production.
  • Oracle Business Intelligence EE integrated with Apache-Tomcat & reverse-proxied transparently through AWS to enable Single Sign-On integration as well.
  • CA Business Objects XI -in essence a re-branded SAP Business Objects flavor tightly integrated with CA Clarity, running on RHEL 4.3 32-bit

• Redmine -various versions and revisions
  • Full setup on CentOS 4.x & 5.x
  • SubVersion -both local and remote instances integrated.
  • mySQL Community Edition as the back-end
  • Ruby-on-Rails
  • AWS as load balancer and reverse-proxy
  • I’ve done quite a bit of custom development on several instances over time to serve some very particular requisites; to mention a few: automatic publishing of revisions to web servers, some custom scripts to automatically run DB DDL & DML against the corresponding target DB instances. For the most part, all done via bash scripting.

• SubVersion
  • Countless repositories setup for professional as well as personal use.

• Custom .NET applications -I can’t be specific here, as I have to respect my client’s non-disclosure and privacy rules.
  • Too numerous to list
  • Most have been enterprise, home-grown applications serving rather specific purposes.
  • Most had in excess of 10,0000 clients
  • IP load balanced and spread across multiple servers and data centers for better availability
  • Microsoft SQL 2000+ & Oracle 10g back-ends.

Little things that I am proud of!

Rescued a highly visible application from certain death.

• The application: a 23/7 public facing application, revenue generating hence business-critical.
• The problem: thousands of transactions committed to a SQL 2005 DB, bulk of transactions were BLOBs -yikes!- storage growing out of control and there was no mechanism built in to safely purge obsolete records nor for archival and retention. The challenge: get storage footprint under control; design and implement a proper archival and long-term retention strategy that allowed online access to such records; and last but not least: NO DOWNTIME ALLOWED ON THE APPLICATION AT ALL.
• The solution: carefully dissected every requirement and attacked them separately; drafted retention and archival policies; devised online data warehouse architecture to support online archival and purging; implemented control mechanisms for audit and performance tracking as well as growth forecasting for the application team to use in the future; executed on the plan.
• The result: almost two years later, the application has cut its storage footprint requirement in half, the DB back-end is humming like an Italian engine and has had zero-down time required -or unexpectedly- since the solution was implemented.

Reconstructing an entire data warehouse from the ground up

• The application: a SQL 2000 instance used as a data warehouse and aggregation point for a rather well-placed client.
• The problem: not 2 months into a client’s project, unrelated to this application, the DB instance goes up in smoke through a bad RAID array that refused to rebuild due to bad parity. The extent and intricacies of the data mining jobs were undocumented, no off site backups existed that could be used to start the rebuild process.
• The solution: armed with a lot of patience, a very good on-site supervisor that knew how to play defense, a very old prototype database snapshot and very very good interpersonal skills, I started the rebuilding effort myself.
• The result: three years later, there is proper documentation of every single process, job, schedule and external dependencies; a proper backup & recovery strategy in place, as well as a cold-backup site that can be turned up and be functional just in time should the worst ever happen again.

Co-designed, architected and ran a b2c ecommerce site

• The business challenge: to securely pre-authorize payment, provision an online service through a SOAP vendor API, secure payment and finally activate service in real time.
• The operational challenge: Keeping fraud in check, quickly identifying and addressing potential risks through social and information engineering. And maintaining a thorough accounting ledger for business and sales & use tax submission -learned quite a bit about Texas SPDs and other miscellaneous tax related shenanigans.
• The end result: an online store that operated successfully and profitably for the better part of 4 years, producing in excess of U$S150K in annual revenues and an increasing profit margin ranging from five percent (on inception) all the way to a healthy 15% through fraud & risk mitigation.

Co-designed, architected and maintained a high-performance prepaid wireless subscriber provisioning system

• The business challenge: to integrate dissimilar vendor interfaces and asynchronous processes to track, provision and maintain prepaid wireless subscriber accounts and balances enabling the company to operate as a Mobile Virtual Network Operator (MVNO), and as such offer multiple prepaid calling plans profitably, while avoiding a multi-million dollar capital investment in infrastructure.
• The technical challenge: integrating dissimilar vendor technologies, ranging from SOAP & REST based web services exposing account provisioning, inquiries and control services and maintaining the highest standard of uptime (the dreaded five 9′s)
• The solution: a modular design that enabled granular billing based on key-trigger events, rapid provisioning, and a unified SOAP-based control interface to expose every aspect of a subscriber account life cycle, that leveraged virtualization and rapid deployment of standby servers.

What I am

An IT professional who is seldom scared or deterred by a new challenge; with a very strong aptitude towards data manipulation -hence my inclination towards the DBA realm.

I’ve participated -and still do occasionally- on industry and technology specific discussion boards and mailing lists. Though I have lost a little bit of faith on some of the communities out there (i.e. Experts-Exchange).

What I am not

I am not the master of the universe and I don’t know everything. I can probably learn it -as I’ve done with things such as CA Clarity PPM- but some things are terribly complex and better suited and left to someone that has done them countless times. For example: I have watched over and done about a half a dozen multi-node RAC installs, but I couldn’t do one right now, even if my life depended on it (in all fairness, I can keep it up & running though).

Here is the obligatory, name dropping, of the platforms, skills & obscure things I’ve worked with over the years, in no particular order.

• Microsoft Windows Server 2000 / 2003 / 2008
  • Active Directory Setup
  • DNS / DHCP & Security Policy Objects
• Microsoft SQL Server 2000 / 2005 / 2008
  • T/SQL Development: adhoc queries, data analysis, stored procedures, functions & triggers.
  • Data mining: SSIS & DTS packages, interops with other RDBM systems.
  • Performance Tuning: tracing capture & analysis with SQL Profiler & Performance Tuning Wizards; indexing & re-indexing; storage & CPU bottleneck analysis.
  • High-availability: mirroring w/SQL Server 2008 & 2005 -experimental; clustered instance support.
  • Backup & Recovery: full & transaction backup strategy planning; Quest LiteSpeed backup compression.
  • Infrastructure: requirements gathering, platform sizing, hybrid implementations (OLTP/OLAP)
  • SSRS: Reporting Services server setup
• Oracle 10g / 11g
  • PL/SQL Development: adhoc queries, data dictionaries, stored procedures, functions & packages.
  • Data mining: SQL Loader & shell scripting
  • Backup & Recovery: Import / Export; archive logging; Recovery MANager.
• CA Clarity PPM 12.x
• SAP Business Objects
• Oracle Business Intelligence Enterprise
• Red Hat Enterprise Linux / CentOS
  • Apache Web Server
  • Apache-Tomcat
  • Oracle (BEA) WebLogic
• Nagios
  • Setup
  • Configuration & custom plug in development
• Configuration Management
  • Visual Source Safe
  • SubVersion
  • Redmine