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Clarify that COPY FREEZE is not a hard rule.

Remove message when FREEZE not honoured,clarify reasons in comments and docs.

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Lines changed: 5 additions & 3 deletions

Original file line number	Diff line number	Diff line change
`@@ -186,17 +186,19 @@ COPY { <replaceable class="parameter">table_name</replaceable> [ ( <replaceable`
`186`	`186`	`<term><literal>FREEZE</literal></term>`
`187`	`187`	`<listitem>`
`188`	`188`	`<para>`
`189`		`-Specifies copying the data with rows already frozen, just as they`
	`189`	`+Requests copying the data with rows already frozen, just as they`
`190`	`190`	`would be after running the <command>VACUUM FREEZE</> command.`
`191`	`191`	`This is intended as a performance option for initial data loading.`
`192`	`192`	`Rows will be frozen only if the table being loaded has been created`
`193`	`193`	`in the current subtransaction, there are no cursors open and there`
`194`	`194`	`are no older snapshots held by this transaction. If those conditions`
`195`	`195`	`are not met the command will continue without error though will not`
`196`		`- freeze rows.`
	`196`	`+ freeze rows. It is also possible in rare cases that the request`
	`197`	`+ cannot be honoured for internal reasons, hence <literal>FREEZE</literal>`
	`198`	`+ is more of a guideline than a hard rule.`
`197`	`199`	`</para>`
`198`	`200`	`<para>`
`199`		`- Note that all sessions will immediately be able to see the data`
	`201`	`+ Note that allothersessions will immediately be able to see the data`
`200`	`202`	`once it has been successfully loaded. This violates the normal rules`
`201`	`203`	`of MVCC visibility and by specifying this option the user acknowledges`
`202`	`204`	`explicitly that this is understood.`

Lines changed: 5 additions & 5 deletions

Original file line number	Diff line number	Diff line change
`@@ -1993,6 +1993,11 @@ CopyFrom(CopyState cstate)`
`1993`	`1993`	`* after xact cleanup. Note that the stronger test of exactly`
`1994`	`1994`	`* which subtransaction created it is crucial for correctness`
`1995`	`1995`	`* of this optimisation.`
	`1996`	`+ *`
	`1997`	`+ * Note that because the test is unreliable in case of relcache reset`
	`1998`	`+ * we cannot guarantee that we can honour the request to FREEZE.`
	`1999`	`+ * If we cannot honour the request we do so silently, firstly to`
	`2000`	`+ * avoid noise for the user and also to avoid obscure test failures.`
`1996`	`2001`	`*/`
`1997`	`2002`	`if (cstate->freeze&&`
`1998`	`2003`	`ThereAreNoPriorRegisteredSnapshots()&&`
`@@ -2001,11 +2006,6 @@ CopyFrom(CopyState cstate)`
`2001`	`2006`	`hi_options \|=HEAP_INSERT_FROZEN;`
`2002`	`2007`	`}`
`2003`	`2008`
`2004`		`-if (cstate->freeze&& (hi_options&HEAP_INSERT_FROZEN)==0)`
`2005`		`-ereport(NOTICE,`
`2006`		`-(errcode(ERRCODE_INVALID_PARAMETER_VALUE),`
`2007`		`-errmsg("FREEZE option specified but pre-conditions not met")));`
`2008`		`-`
`2009`	`2009`	`/*`
`2010`	`2010`	`* We need a ResultRelInfo so we can use the regular executor's`
`2011`	`2011`	`* index-entry-making machinery. (There used to be a huge amount of code`

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