diff options
Diffstat (limited to 'src/bin/pg_dump/pg_dump.c')
| -rw-r--r-- | src/bin/pg_dump/pg_dump.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index e844b5b0624..d3eb7662880 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -11,14 +11,14 @@ * script that reproduces the schema in terms of SQL that is understood * by PostgreSQL * - * Note that pg_dump runs in a serializable transaction, so it sees a - * consistent snapshot of the database including system catalogs. - * However, it relies in part on various specialized backend functions - * like pg_get_indexdef(), and those things tend to run on SnapshotNow - * time, ie they look at the currently committed state. So it is - * possible to get 'cache lookup failed' error if someone performs DDL - * changes while a dump is happening. The window for this sort of thing - * is from the beginning of the serializable transaction to + * Note that pg_dump runs in a transaction-snapshot mode transaction, + * so it sees a consistent snapshot of the database including system + * catalogs. However, it relies in part on various specialized backend + * functions like pg_get_indexdef(), and those things tend to run on + * SnapshotNow time, ie they look at the currently committed state. So + * it is possible to get 'cache lookup failed' error if someone + * performs DDL changes while a dump is happening. The window for this + * sort of thing is from the acquisition of the transaction snapshot to * getSchemaData() (when pg_dump acquires AccessShareLock on every * table it intends to dump). It isn't very large, but it can happen. * @@ -135,6 +135,7 @@ static int dump_inserts = 0; static int column_inserts = 0; static int no_security_label = 0; static int no_unlogged_table_data = 0; +static int serializable_deferrable = 0; static void help(const char *progname); @@ -318,6 +319,7 @@ main(int argc, char **argv) {"no-tablespaces", no_argument, &outputNoTablespaces, 1}, {"quote-all-identifiers", no_argument, "e_all_identifiers, 1}, {"role", required_argument, NULL, 3}, + {"serializable-deferrable", no_argument, &serializable_deferrable, 1}, {"use-set-session-authorization", no_argument, &use_setsessauth, 1}, {"no-security-label", no_argument, &no_security_label, 1}, {"no-unlogged-table-data", no_argument, &no_unlogged_table_data, 1}, @@ -669,11 +671,21 @@ main(int argc, char **argv) no_security_label = 1; /* - * Start serializable transaction to dump consistent data. + * Start transaction-snapshot mode transaction to dump consistent data. */ do_sql_command(g_conn, "BEGIN"); - - do_sql_command(g_conn, "SET TRANSACTION ISOLATION LEVEL SERIALIZABLE"); + if (g_fout->remoteVersion >= 90100) + { + if (serializable_deferrable) + do_sql_command(g_conn, + "SET TRANSACTION ISOLATION LEVEL SERIALIZABLE, " + "READ ONLY, DEFERRABLE"); + else + do_sql_command(g_conn, + "SET TRANSACTION ISOLATION LEVEL REPEATABLE READ"); + } + else + do_sql_command(g_conn, "SET TRANSACTION ISOLATION LEVEL SERIALIZABLE"); /* Select the appropriate subquery to convert user IDs to names */ if (g_fout->remoteVersion >= 80100) @@ -864,6 +876,7 @@ help(const char *progname) printf(_(" --disable-triggers disable triggers during data-only restore\n")); printf(_(" --no-tablespaces do not dump tablespace assignments\n")); printf(_(" --quote-all-identifiers quote all identifiers, even if not keywords\n")); + printf(_(" --serializable-deferrable wait until the dump can run without anomalies\n")); printf(_(" --role=ROLENAME do SET ROLE before dump\n")); printf(_(" --no-security-label do not dump security label assignments\n")); printf(_(" --no-unlogged-table-data do not dump unlogged table data\n")); |