Oracle Dynamic ID Generator For Spring Boot

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2026-07-11 English 0 toplam yorum

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Oracle Dynamic ID Generator For Spring Boot

#OpenSource #Oracle #medium #Spring #Kotlin

The main idea is to:

use a reusable custom IdentifierGenerator
determine Oracle sequence names dynamically from entity metadata
fetch IDs either one by one or in batches
keep a small in-memory pool of prefetched IDs to reduce database round trips during bulk inserts
support JDBC batching efficiently

The project compares two different approaches side-by-side:

Dynamic custom sequence generation (User)
Standard JPA @SequenceGenerator (Role)

This makes the project useful as a reference for teams that want flexible Oracle ID generation without hardcoding a sequence generator on every entity.

Problem the Project Solves

When using Oracle with JPA/Hibernate, sequence-based IDs are common. However, the default approach usually requires every entity to declare its own fixed configuration, for example:

@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ\_USER\_GENERATOR")  
@SequenceGenerator(name = "SEQ\_USER\_GENERATOR", sequenceName = "users\_seq", allocationSize = 1)

This works well but becomes repetitive when many entities follow a naming convention such as:

table users -> sequence users_seq
table orders -> sequence orders_seq
table customers -> sequence customers_seq

This project centralizes sequence handling in a reusable generator so that the application can:

derive the sequence name automatically
support bulk insert scenarios more efficiently
keep entity definitions simpler
still work with Oracle sequence semantics

Core Solution

Custom Hibernate ID Generator

The core component is DynamicSequenceGenerator. Its responsibilities are:

inspect the entity being persisted
resolve the Oracle sequence name dynamically
fetch the next sequence value from Oracle
optionally fetch multiple IDs in a single SQL query
cache prefetched IDs in an in-memory queue

The generator is attached to the User entity through:

@GeneratedValue(generator = "dynamic-seq")  
@GenericGenerator(name = "dynamic-seq", strategy = "com.github.senocak.DynamicSequenceGenerator")

Dynamic Sequence Name Resolution

The generator determines the sequence name using conventions:

if the entity contains @Table(name = “…”) use <table_name>_seq
otherwise, use <entity_class_name_lowercase>_seq

This means the sequence naming rule is defined once in the generator rather than repeated across all entities.

Batch-Aware ID Fetching

For bulk insert operations, the generator can fetch multiple IDs in one Oracle query:

SELECT users_seq.NEXTVAL FROM dual CONNECT BY LEVEL <= ?

Returned IDs are stored in a temporary in-memory queue and reused during persistence. This reduces database round trips significantly compared with fetching IDs one-by-one.

Thread-Local Batch Context

IdGenerationContext stores the desired batch size using ThreadLocal. Before calling saveAll, the app sets the batch size for the current work unit. The generator reads that value and decides whether to:

fetch a single ID
or fetch a batch of IDs into the local pool

After persistence, the thread-local state is cleared to avoid leaking configuration into later operations.

Dynamic ID Generation Details

Single ID path

If batchSize <= 1, the generator executes:

SELECT <sequence>.NEXTVAL FROM dual

This is the simple path for one-at-a-time inserts.

Batch path

If batchSize > 1, the generator executes:

SELECT <sequence>.NEXTVAL FROM dual CONNECT BY LEVEL <= ?

The returned values are stored in an internal queue and reused by later generate() calls.

Why this is useful

Benefits:

fewer Oracle calls during bulk insert operations
reusable convention-based ID strategy
less annotation repetition across entities
easy to adapt for multiple tables following the same sequence naming rule

Summary

This application demonstrates a Dynamic Oracle ID generation strategy for Spring Boot and Kotlin. Its main contribution is a custom Hibernate generator that:

derives sequence names dynamically
supports bulk ID prefetching
uses Oracle efficiently during batched persistence
keeps entity configuration simpler when a naming convention is available In short, it is a compact reference implementation of dynamic sequence-based ID generation with Spring Boot, Kotlin, Hibernate, and Oracle.

For custom implementation;

2026-05-27T23:21:33.780+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:4, Time:75, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["SELECT users_seq.NEXTVAL FROM dual CONNECT BY LEVEL <= ?"]
Params:[(5)]
2026-05-27T23:21:33.783+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Fetched 5 ids into local pool (requested 5). Returning id after batch fetch: 1
2026-05-27T23:21:33.800+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 2
2026-05-27T23:21:33.801+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 3
2026-05-27T23:21:33.801+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 4
2026-05-27T23:21:33.802+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 5
2026-05-27T23:21:33.836+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:4, Time:14, Success:True
Type:Prepared, Batch:True, QuerySize:1, BatchSize:5
Query:["insert into users (name,id) values (?,?)"]
Params:[(John 1 0,1),(John 2 1,2),(John 3 2,3),(John 4 3,4),(John 5 4,5)]
2026-05-27T23:21:33.849+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:5, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["SELECT users_seq.NEXTVAL FROM dual CONNECT BY LEVEL <= ?"]
Params:[(5)]
2026-05-27T23:21:33.849+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Fetched 5 ids into local pool (requested 5). Returning id after batch fetch: 6
2026-05-27T23:21:33.850+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 7
2026-05-27T23:21:33.850+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 8
2026-05-27T23:21:33.850+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 9
2026-05-27T23:21:33.850+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 10
2026-05-27T23:21:33.858+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:5, Time:7, Success:True
Type:Prepared, Batch:True, QuerySize:1, BatchSize:5
Query:["insert into users (name,id) values (?,?)"]
Params:[(John 6 0,6),(John 7 1,7),(John 8 2,8),(John 9 3,9),(John 10 4,10)]
2026-05-27T23:21:33.875+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:6, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["SELECT users_seq.NEXTVAL FROM dual CONNECT BY LEVEL <= ?"]
Params:[(2)]
2026-05-27T23:21:33.875+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Fetched 2 ids into local pool (requested 2). Returning id after batch fetch: 11
2026-05-27T23:21:33.876+03:00  INFO 49079 --- [SpringKotlinOracle] [           main] c.g.senocak.DynamicSequenceGenerator     : Returning id from local pool: 12
2026-05-27T23:21:33.882+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:6, Time:4, Success:True
Type:Prepared, Batch:True, QuerySize:1, BatchSize:2
Query:["insert into users (name,id) values (?,?)"]
Params:[(John 11 0,11),(John 12 1,12)]

For traditional implementation;

2026-05-27T23:21:38.967+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:20, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.971+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.973+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.974+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.976+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.977+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.978+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.979+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.991+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:11, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.992+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.993+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:38.994+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:False, QuerySize:1, BatchSize:0
Query:["select users_seq.nextval"]
Params:[()]
2026-05-27T23:21:39.009+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:12, Success:True
Type:Prepared, Batch:True, QuerySize:1, BatchSize:10
Query:["insert into roles (name,id) values (?,?)"]
Params:[(John 0,13),(John 1,14),(John 2,15),(John 3,16),(John 4,17),(John 5,18),(John 6,19),(John 7,20),(John 8,21),(John 9,22)]
2026-05-27T23:21:39.010+03:00 DEBUG 49079 --- [SpringKotlinOracle] [           main] n.t.d.l.l.SLF4JQueryLoggingListener      : 
Name:dataSource, Connection:7, Time:0, Success:True
Type:Prepared, Batch:True, QuerySize:1, BatchSize:2
Query:["insert into roles (name,id) values (?,?)"]
Params:[(John 10,23),(John 11,24)]