Packages and state
- Packages become schemas of related functions
- Package variables move to session settings or temporary tables
- Package initialization code becomes an explicit setup call
Oracle Database Services
Oracle Database upgrade and migration services
When an Oracle Database release leaves Premier Support, teams must choose between upgrading, moving to a managed service and leaving Oracle altogether. Agnotic Technologies helps you make that choice from the evidence in your own schemas, then carries out the upgrade or migration and the cutover.
Upgrade, managed or PostgreSQLPL/SQL conversionCDC cutover with rollbackQuery plan testing
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Oracle databases
What do Oracle database services include?
Oracle database services are the planning and engineering work that keeps Oracle databases supported and fast, or moves them somewhere else. Agnotic Technologies assesses your schemas, PL/SQL and workload, recommends an in-place upgrade, a managed Oracle service or a PostgreSQL migration, and carries out the conversion, data move, testing and cutover.
This page is about Oracle Database. Oracle Health (Cerner) is a separate electronic health record product with its own integration work.
We do not resell licences or estimate licence savings. Your licensing team or Oracle confirms the licence position for each option; we show what each option changes in code, risk and day-to-day operations.
Decision table
Should you upgrade Oracle, move to managed Oracle or migrate to PostgreSQL?
The three options we compare for every database. The answer can differ between databases in the same estate.
| Option | Licensing exposure | Code change | Main risk | When it fits |
|---|---|---|---|---|
| Upgrade in place to a supported release | Unchanged; current licences and support contract stay | Low: deprecated features and parameter changes | Query plans that change after the optimizer upgrade | The database is healthy, the team knows Oracle and the servers have life left |
| Managed Oracle, such as Amazon RDS for Oracle or Oracle's own cloud database services | Licence included for some editions, or bring your own licence | Low to medium: features the service restricts, such as operating system access | Code that depends on something the managed service does not allow | You want patching, backups and failover handled, but the code depends on Oracle |
| Migrate to PostgreSQL | Oracle licences can be retired once cutover is complete | High: schema, PL/SQL, SQL dialect and drivers | Behaviour differences found late, such as empty string and NULL handling | The PL/SQL estate is manageable, or the database is being rebuilt with the application |
We never recommend a migration on licence cost alone. The size of the PL/SQL inventory decides how big the move really is.
PL/SQL to PL/pgSQL
What has to change when Oracle code moves to PostgreSQL?
Items we find in almost every Oracle schema, and how we convert them.
Data types
- VARCHAR2 becomes varchar or text
- NUMBER maps to integer, bigint or numeric by how each column is used
- Oracle DATE holds a time of day, so it usually maps to timestamp
- Oracle treats an empty string as NULL and PostgreSQL does not, so those checks are rewritten
Sequences and keys
- Sequences recreated with their current values at cutover
- Identity columns where the application allows
- Triggers that fill keys replaced with column defaults
SQL dialect
- ROWNUM and CONNECT BY rewritten as LIMIT and recursive queries
- The (+) outer join syntax rewritten as ANSI joins
- Optimizer hints removed and the plans tested again
- DUAL and Oracle date functions replaced
Application side
- JDBC or ODBC drivers and connection pool settings
- Database error codes the application catches
- Jobs that relied on DBMS_JOB or DBMS_SCHEDULER
Migration steps
How does an Oracle to PostgreSQL migration run?
The same five steps for every database, with a way back until the rollback window closes.
Inventory and assess
We list schemas, objects, PL/SQL, database links and jobs per database, and flag what automated conversion cannot handle.
Convert schema and code
Schema conversion tools do the first pass; our engineers convert the rest by hand and write a test for each converted routine.
Load and replicate
A full load copies the data, then change data capture keeps PostgreSQL in step with Oracle while testing runs.
Compare results and performance
We compare query results row by row and replay the production workload against both, reading query plans where timings differ.
Cut over with a way back
Writes move to PostgreSQL in a short window, and reverse replication to Oracle stays ready until the rollback window closes.
Who it is for
Who do we help with Oracle databases?
Teams that need a decision and the engineering to carry it out.
Teams facing the end of Premier Support
Databases on a release that is leaving Premier Support, with an upgrade or a move to plan.
Companies leaving their data centers
Oracle workloads moving to a cloud, kept on Oracle or moved to PostgreSQL.
Product companies leaving Oracle
Software vendors who want PostgreSQL under their product for new and existing customers.
Teams with slow Oracle workloads
Query and index tuning, statistics and plan stability on the current release.
Enterprises consolidating databases
Many small Oracle databases merged, retired or moved as one program.
Failure points
What goes wrong in Oracle upgrades and migrations?
Problems we plan for on every Oracle project.
Challenge
A query that ran fast slows down badly after the upgrade.
Agnotic approach
We capture plans before the upgrade and compare them on the new release before go-live, fixing regressions with statistics, indexes or rewrites.
Challenge
Converted code compiles but returns different results.
Agnotic approach
Every converted routine runs against the same inputs on both databases, with results compared automatically.
Challenge
The cutover window is too short for a full copy.
Agnotic approach
Change data capture replicates changes continuously, so cutover waits only for the last few transactions.
Challenge
Hidden dependencies, such as database links or reporting tools, break after the move.
Agnotic approach
The inventory includes every client seen in the database's session and audit records over a full business cycle.
Challenge
Licensing assumptions turn out wrong late in the project.
Agnotic approach
Your licensing team confirms the position for each option at the decision stage, before any build work starts.
Platforms and tools
Which databases and migration tools do we work with?
The platforms behind the options in the decision table.
Oracle DatabasePostgreSQLAmazon RDS for OracleOracle Cloud InfrastructureAWS DMSAWS SCT
Facts and sources
Facts behind Oracle database upgrades and migrations
Support policy and vendor documentation, each linked to its primary source.
Oracle Premier Support for Oracle Database provides maintenance and software upgrades for five years from a release's general availability date; Extended Support adds maintenance for an additional fee, and Sustaining Support continues for as long as the software is used.
Source: Oracle Lifetime Support PolicyAmazon RDS for Oracle has two licensing options: License Included, supported only for Standard Edition 2, and Bring Your Own License for Enterprise Edition and Standard Edition 2.
Source: Amazon RDS User Guide: RDS for Oracle licensing optionsPostgreSQL has no packages, so its guide to porting from Oracle PL/SQL recommends schemas to group functions and temporary tables for the per-session state that package variables used to hold.
Source: PostgreSQL documentation: Porting from Oracle PL/SQLAWS Database Migration Service captures ongoing changes from an Oracle source with either Oracle LogMiner or AWS DMS Binary Reader, and the choice decides some of the permissions and configuration the source needs.
Source: AWS DMS User Guide: using an Oracle database as a sourceThe AWS Schema Conversion Tool converts an existing database schema from one database engine to another, with targets that include Amazon RDS for PostgreSQL and Amazon Aurora.
Source: AWS Schema Conversion Tool User Guide
Scope and cost
What drives the cost of an Oracle database project?
Prices are not published. Each factor below changes how much work a database needs, and we size them per database on the scoping call.
Number and size of databases
How many databases move, and how much data and change volume each holds.
PL/SQL volume
How much procedural code exists and how much of it uses Oracle-only features.
Oracle features in use
Partitioning, Advanced Queuing, spatial data or other features that need a design decision on the target.
Downtime allowed
How short the cutover window must be, which decides how much replication work is needed.
Application changes
Drivers, SQL embedded in code and error handling in the applications that use each database.
Test data and environments
Whether a production-sized copy can be used for testing, and how it is masked.
Frequently Asked Questions
We do not publish prices. Cost depends on the number and size of databases, the volume of PL/SQL, the Oracle features in use, the downtime you can accept and the application changes needed. After the scoping call you receive a written proposal per database or for the whole estate.
When your release leaves Premier Support and you do not want to pay for Extended Support, or when a platform you depend on drops the release. Check the Oracle Lifetime Support Policy for your release and plan the upgrade before that date.
Partly. Conversion tools handle most tables, indexes and simple routines. Packages, dynamic SQL, autonomous transactions and Oracle-only built-in packages need an engineer, and every converted routine needs a test.
It depends on write volume and how much checking you want inside the window. With change data capture the data is already in step, so the window covers stopping writes, the final catch-up, checks and switching connections. We agree it with you during planning.
Yes. Amazon RDS for Oracle and Oracle's own cloud database services run Oracle Database with patching and backups managed for you. We check which features your code uses that a managed service restricts.
Oracle Health is a different product: an electronic health record, not a database. This page covers Oracle Database. Integration with the Oracle Health EHR is part of our healthcare integration work.