wjones
a18c6a7386
- Implement pg_vtab as a minimal SQLite virtual table module backed by PostgreSQL. - Create sqlite2pgsql utility for copying tables from SQLite to PostgreSQL. - Add sqlite_pg_plugin to expose PostgreSQL tables to SQLite. - Include Makefile for building the pg_vtab shared object. - Update README with usage instructions and limitations. - Remove obsolete cache.zip file.
39 lines
1.2 KiB
Markdown
39 lines
1.2 KiB
Markdown
# SQLite -> PostgreSQL virtual table (minimal)
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This directory contains a minimal SQLite extension that implements a read-only virtual table backed directly by PostgreSQL using libpq.
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Build
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-----
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You need `libpq` (Postgres client) and a C compiler. On Debian/Ubuntu:
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```bash
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sudo apt-get install libpq-dev build-essential
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make
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```
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This produces `pg_vtab.so`.
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Usage
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-----
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Start `sqlite3`, load the extension and create a virtual table pointing at a Postgres table:
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```sql
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.load ./pg_vtab.so
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CREATE VIRTUAL TABLE remote_tbl USING pg_vtab('host=localhost dbname=mydb user=me password=secret', 'public.mytable');
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SELECT * FROM remote_tbl LIMIT 10;
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```
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Limitations
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-----------
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- Minimal proof-of-concept: supports only full table scans.
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- All columns are presented as `TEXT`.
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- No constraint pushdown or type mapping sophistication.
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- Error handling and SQL injection hygiene are minimal; do not use on untrusted inputs without review.
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Next steps (optional)
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---------------------
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- Add support for WHERE constraints and indexed access (`xBestIndex`).
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- Map Postgres types more accurately to SQLite storage classes.
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- Implement server-side cursors for large tables.
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- Harden error reporting and resource cleanup.
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