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Commit 73a6005

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tglsfdctglsfdc
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Doc: warn against using parallel restore with --load-via-partition-root.
This isn't terribly safe, and making it so doesn't seem like a small project, so for the moment just warn against it. Discussion: https://postgr.es/m/13624.1535486019@sss.pgh.pa.us
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‎doc/src/sgml/ref/pg_dump.sgml

Copy file name to clipboardExpand all lines: doc/src/sgml/ref/pg_dump.sgml
+21-8Lines changed: 21 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -793,13 +793,26 @@ PostgreSQL documentation
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<term><option>--load-via-partition-root</option></term>
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<listitem>
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<para>
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When dumping a <command>COPY</command> or <command>INSERT</command> statement for a partitioned table,
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target the root of the partitioning hierarchy which contains it rather
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than the partition itself. This may be useful when reloading data on
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a server where rows do not always fall into the same partitions as
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they did on the original server. This could happen, for example, if
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the partitioning column is of type text and the two system have
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different definitions of the collation used to partition the data.
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When dumping data for a table partition, make
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the <command>COPY</command> or <command>INSERT</command> statements
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target the root of the partitioning hierarchy that contains it, rather
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than the partition itself. This causes the appropriate partition to
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be re-determined for each row when the data is loaded. This may be
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useful when reloading data on a server where rows do not always fall
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into the same partitions as they did on the original server. That
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could happen, for example, if the partitioning column is of type text
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and the two systems have different definitions of the collation used
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to sort the partitioning column.
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</para>
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<para>
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It is best not to use parallelism when restoring from an archive made
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with this option, because <application>pg_restore</application> will
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not know exactly which partition(s) a given archive data item will
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load data into. This could result in inefficiency due to lock
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conflicts between parallel jobs, or perhaps even reload failures due
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to foreign key constraints being set up before all the relevant data
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is loaded.
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</para>
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</listitem>
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</varlistentry>
@@ -915,7 +928,7 @@ PostgreSQL documentation
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<para>
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Add <literal>ON CONFLICT DO NOTHING</literal> to
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<command>INSERT</command> commands.
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This option is not valid unless <option>--inserts</option> or
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This option is not valid unless <option>--inserts</option> or
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<option>--column-inserts</option> is also specified.
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</para>
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</listitem>

‎doc/src/sgml/ref/pg_dumpall.sgml

Copy file name to clipboardExpand all lines: doc/src/sgml/ref/pg_dumpall.sgml
+15-8Lines changed: 15 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -330,14 +330,21 @@ PostgreSQL documentation
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<term><option>--load-via-partition-root</option></term>
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<listitem>
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<para>
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When dumping a <command>COPY</command> or <command>INSERT</command> statement for a partitioned table,
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target the root of the partitioning hierarchy which contains it rather
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than the partition itself. This may be useful when reloading data on
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a server where rows do not always fall into the same partitions as
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they did on the original server. This could happen, for example, if
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the partitioning column is of type text and the two system have
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different definitions of the collation used to partition the data.
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When dumping data for a table partition, make
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the <command>COPY</command> or <command>INSERT</command> statements
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target the root of the partitioning hierarchy that contains it, rather
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than the partition itself. This causes the appropriate partition to
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be re-determined for each row when the data is loaded. This may be
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useful when reloading data on a server where rows do not always fall
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into the same partitions as they did on the original server. That
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could happen, for example, if the partitioning column is of type text
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and the two systems have different definitions of the collation used
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to sort the partitioning column.
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</para>
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<!-- Currently, we don't need pg_dump's warning about parallelism here,
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since parallel restore from a pg_dumpall script is impossible.
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-->
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</listitem>
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</varlistentry>
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@@ -452,7 +459,7 @@ PostgreSQL documentation
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<para>
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Add <literal>ON CONFLICT DO NOTHING</literal> to
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<command>INSERT</command> commands.
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This option is not valid unless <option>--inserts</option> or
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This option is not valid unless <option>--inserts</option> or
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<option>--column-inserts</option> is also specified.
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</para>
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</listitem>

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