SPI_CURSOR_OPEN(3)

🌸 SPI_CURSOR_OPEN(3) 🌸

Okay bestie, welcome to the SPI_CURSOR_OPEN(3) page from the PostgreSQL 17.11 Documentation — yes, section 3, we’re in full Unix manual mode. 💅

✨ NAME ✨

SPI_cursor_open — set up a cursor using a statement created with SPI_prepare. 🫶

💖 SYNOPSIS 💖

       Portal SPI_cursor_open(const char * name, SPIPlanPtr plan,
                              Datum * values, const char * nulls,
                              bool read_only)

🦋 DESCRIPTION 🦋

Okay so SPI_cursor_open sets up a cursor (internally, a portal) that will execute a statement prepared by SPI_prepare. The parameters have the same meanings as the corresponding parameters to SPI_execute_plan. No cap. ✨

Using a cursor instead of executing the statement directly has two benefits. First, the result rows can be retrieved a few at a time, avoiding memory overrun for queries that return many rows. Second, a portal can outlive the current C function (it can, in fact, live to the end of the current transaction). Returning the portal name to the C function’s caller provides a way of returning a row set as result. Literally iconic. 👑

The passed-in parameter data will be copied into the cursor’s portal, so it can be freed while the cursor still exists. 💖

🎀 ARGUMENTS 🎀

• const char * name — name for portal, or NULL to let the system select a name. 🎀
• SPIPlanPtr plan — prepared statement (returned by SPI_prepare). ✨
• Datum * values — An array of actual parameter values. Must have same length as the statement’s number of arguments. 🍓
• const char * nulls — An array describing which parameters are null. Must have same length as the statement’s number of arguments.

If nulls is NULL then SPI_cursor_open assumes that no parameters are null. Otherwise, each entry of the nulls array should be ' ' if the corresponding parameter value is non-null, or 'n' if the corresponding parameter value is null. (In the latter case, the actual value in the corresponding values entry doesn’t matter.) Note that nulls is not a text string, just an array: it does not need a '\0' terminator. 🧚

• bool read_only — true for read-only execution. 💜

🌈 RETURN VALUE 🌈

Pointer to portal containing the cursor. Note there is no error return convention; any error will be reported via elog. 😭

xoxo, this page is from PostgreSQL 17.11 docs, dated 2026 — slay and stay safe, bestie. 💖✨