Convert pg_dump to DuckDB

Upload a .backup or .dump file and get back a DuckDB file. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.

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CSV, Excel, SQLite, SQL, DBF (max 10 MB)

How your data is typed in DuckDB

Generated from the converter's own DuckDB type mapping — this is what it actually emits, not an example.

Your dataDuckDB type
Whole numberBIGINT
Decimal (money)DECIMAL(10,2)
Floating pointDOUBLE
True / falseBOOLEAN
DateDATE
Date and timeTIMESTAMP
Short textVARCHAR
Long textVARCHAR
Binary dataBLOB

Working from a pg_dump file

pg_dump has enough flags to change what its output even contains, and a few of them decide whether the file in front of you is convertible at all. These are the ones that matter here.

  • pg_dump -Fc and a plain pg_dump > file.sql both work, and so does --inserts or --column-inserts, though neither is necessary: the default COPY output is read too.
  • --schema-only gives you the tables with no rows in them. That is a valid conversion, and almost never the one that was wanted.
  • --data-only is the opposite problem: rows arrive with no CREATE TABLE to name their columns, and the conversion says so rather than inventing names for them.
  • Ownership and privilege statements are dropped while the archive is unpacked, so a dump taken as one role converts without that role having to exist anywhere.

Decimals and text in the .duckdb file

DuckDB takes the source's declared types more nearly unchanged than any other target here, which makes the two places where it cannot the things worth reading: the width of a decimal, and the length of a string.

  • DECIMAL tops out at 38 digits, so a wider source column is clamped rather than refused: an Oracle NUMBER(50,10) is created here as DECIMAL(38,10), and the scale is never allowed to grow past the precision holding it.
  • A decimal that declared no scale gets six places for its fraction rather than none, inside that same rule: a source precision of 10 becomes DECIMAL(10,6), one of 5 becomes DECIMAL(5,5), and one that declared no precision either becomes DECIMAL(18,6).
  • Strings become VARCHAR with no length attached to them. DuckDB's VARCHAR is unbounded, so no column has to be sized in advance and no row can be turned away for being longer than the column it goes in.

Reading pg_dump

  • Reads pg_dump custom-format archives (.backup, .dump) — pgAdmin's default backup option — as well as plain SQL dumps.
  • Data written as COPY blocks is read, not just INSERT statements. COPY is pg_dump's default, so a reader that only understands INSERT returns your tables with none of their rows.
  • Primary keys declared by a later ALTER TABLE, which is how pg_dump writes them, are preserved.

Writing DuckDB

  • A real .duckdb file, not a script — open it straight away with the DuckDB CLI.
  • DuckDB has genuine DECIMAL and BOOLEAN types, so nothing is flattened on the way in.

What you get

A ZIP containing database.duckdb. If anything about your data needed a judgement call, a _warnings.txt explains it.

Questions

Is converting pg_dump to DuckDB free?
Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.
Will my pg_dump data keep its types in DuckDB?
Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real DuckDB types rather than everything becoming text. The mapping table above shows exactly what you get.
Do you store my file?
No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.

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