How Can I Merge Two Arrays of Equal Length into a Two-Dimensional Array in PostgreSQL?

Combining Arrays with Zip-Like Functionality in PostgreSQL

Question: Is there a specialized function in PostgreSQL that merges two arrays of equal length into a two-dimensional array?

Answer:

Postgres 9.5 and Later

Introducing array_agg(array expression), a powerful tool that combines all input arrays into a single array of one higher dimension. This function has effectively replaced the need for custom aggregate functions like array_agg_mult().

Postgres 9.4

Utilize ROWS FROM or the enhanced unnest() function to unnest multiple arrays concurrently. The resulting array size will match the largest input array, with smaller arrays padded with null values.

Postgres 9.3 and Earlier

Simple Zip() for One-Dimensional Array:

Leverage the unnest() function to create a simple zip() functionality that unnests two arrays in parallel. This approach works effectively as long as the arrays have an equal number of elements.

Zip() for Multi-Dimensional Array:

Combining the unnested arrays into a two-dimensional array requires a custom aggregate function like array_agg_mult(). This function aggregates individual arrays into a multi-dimensional array. To utilize this function for zip() functionality, wrap it in a separate function,

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