Update max_protocol_version and min_protocol_version defaults#2526
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abrightwell wants to merge 1 commit intojackc:masterfrom
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Update max_protocol_version and min_protocol_version defaults#2526abrightwell wants to merge 1 commit intojackc:masterfrom
max_protocol_version and min_protocol_version defaults#2526abrightwell wants to merge 1 commit intojackc:masterfrom
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When `max_protocol_version` is not explicitly set, the default value is set to "3.0". This is reasonable and is inline with the same behavior as libpq[1]. Though, what libpq attempts to do that was not being done here is to reasonably upgrade or auto-raise the value of `max_protocol_version` when it has not been explicitly set. Here, we're providing the same functionality. In libpq, this determination is based on the parsed config values. We do the same here, parsing the values in ParseConfig to validate and determine the appropriate default for max_protocol_version. The string fields on Config are then set accordingly, and re-parsed at connection time as before. After parsing, when `max_protocol_version` has not been explicitly set, if `min_protocol_version` is greater than 3.0, `max_protocol_version` defaults to `latest`; otherwise it defaults to 3.0 for compatibility with older servers/poolers that don't support NegotiateProtocolVersion. [1] postgres/postgres@285613c
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Mar 26, 2026
| const ( | ||
| ProtocolVersion30 = 196608 // 3.0 | ||
| ProtocolVersion32 = 196610 // 3.2 | ||
| ProtocolVersionLatest = ProtocolVersion32 // Latest is 3.2 |
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Not necessary for this change. But as I was working through attempting to remove the double-parse requirement, I had added it. Certainly could remove it but felt like it was a potential gap that was worth filling.
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When
max_protocol_versionis not explicitly set, the default value is set to "3.0". This is reasonable and is inline with the same behavior as libpq[1]. Though, what libpq attempts to do that was not being done here is to reasonably upgrade or auto-raise the value ofmax_protocol_versionwhen it has not been explicitly set.Here, we're providing the same functionality. In libpq, this determination is based on the parsed config values. We do the same here, parsing the values in ParseConfig to validate and determine the appropriate default for max_protocol_version. The string fields on Config are then set accordingly, and re-parsed at connection time as before.
After parsing, when
max_protocol_versionhas not been explicitly set, ifmin_protocol_versionis greater than 3.0,max_protocol_versiondefaults tolatest; otherwise it defaults to 3.0 for compatibility with older servers/poolers that don't support NegotiateProtocolVersion.[1] postgres/postgres@285613c
Fixes: #2525