From a7b90d36b64021315c09a15d17f8cf26a6e72fe7 Mon Sep 17 00:00:00 2001 From: Wu Haotian Date: Thu, 1 Apr 2021 17:14:29 +0800 Subject: [PATCH] pg_dump/restore: add --drop-cascade option This option makes pg_dump and pg_store inject a CASCADE clause to each DROP command. This allows for restoring an old backup after adding new constraints, at the risk of losing new data. --- doc/src/sgml/ref/pg_dump.sgml | 10 ++ doc/src/sgml/ref/pg_restore.sgml | 10 ++ src/bin/pg_dump/pg_backup.h | 2 + src/bin/pg_dump/pg_backup_archiver.c | 157 ++++++++++++++------------- src/bin/pg_dump/pg_dump.c | 6 + src/bin/pg_dump/pg_restore.c | 10 ++ src/bin/pg_dump/t/001_basic.pl | 7 +- src/bin/pg_dump/t/002_pg_dump.pl | 147 +++++++++++++++++-------- 8 files changed, 228 insertions(+), 121 deletions(-) diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml index 529b167c96..b486c26e39 100644 --- a/doc/src/sgml/ref/pg_dump.sgml +++ b/doc/src/sgml/ref/pg_dump.sgml @@ -732,6 +732,16 @@ PostgreSQL documentation + + + + + Use CASCADE to drop database objects. + This option is not valid unless is also specified. + + + + diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml index 93ea937ac8..d52067a149 100644 --- a/doc/src/sgml/ref/pg_restore.sgml +++ b/doc/src/sgml/ref/pg_restore.sgml @@ -553,6 +553,16 @@ PostgreSQL documentation + + + + + Use CASCADE to drop database objects. + This option is not valid unless is also specified. + + + + diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h index 3bc86635f7..f06ea051a3 100644 --- a/src/bin/pg_dump/pg_backup.h +++ b/src/bin/pg_dump/pg_backup.h @@ -83,6 +83,7 @@ typedef struct _restoreOptions * instead of OWNER TO */ char *superuser; /* Username to use as superuser */ char *use_role; /* Issue SET ROLE to this */ + int drop_cascade; int dropSchema; int disable_dollar_quoting; int dump_inserts; /* 0 = COPY, otherwise rows per INSERT */ @@ -152,6 +153,7 @@ typedef struct _dumpOptions /* flags for various command-line long options */ int disable_dollar_quoting; + int drop_cascade; int column_inserts; int if_exists; int no_comments; diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c index 86de26a4bf..68c38eae49 100644 --- a/src/bin/pg_dump/pg_backup_archiver.c +++ b/src/bin/pg_dump/pg_backup_archiver.c @@ -187,6 +187,7 @@ dumpOptionsFromRestoreOptions(RestoreOptions *ropt) dopt->cparams.promptPassword = ropt->cparams.promptPassword; dopt->outputClean = ropt->dropSchema; dopt->dataOnly = ropt->dataOnly; + dopt->drop_cascade = ropt->drop_cascade; dopt->schemaOnly = ropt->schemaOnly; dopt->if_exists = ropt->if_exists; dopt->column_inserts = ropt->column_inserts; @@ -528,95 +529,103 @@ RestoreArchive(Archive *AHX) */ if (*te->dropStmt != '\0') { - if (!ropt->if_exists) + if (!ropt->if_exists && !ropt->drop_cascade) { - /* No --if-exists? Then just use the original */ + /* Just use the original */ ahprintf(AH, "%s", te->dropStmt); } + /* + * Inject an appropriate spelling of "if exists" or "cascade". + * For large objects, we have a separate routine that + * knows how to do it, without depending on + * te->dropStmt; use that. For other objects we need + * to parse the command. + */ + else if (strncmp(te->desc, "BLOB", 4) == 0) + { + if (ropt->if_exists) + DropBlobIfExists(AH, te->catalogId.oid); + else + ahprintf(AH, "%s", te->dropStmt); + } else { + char *dropStmt = pg_strdup(te->dropStmt); + char *dropStmtOrig = dropStmt; + PQExpBuffer ftStmt = createPQExpBuffer(); /* - * Inject an appropriate spelling of "if exists". For - * large objects, we have a separate routine that - * knows how to do it, without depending on - * te->dropStmt; use that. For other objects we need - * to parse the command. - */ - if (strncmp(te->desc, "BLOB", 4) == 0) + * Need to inject IF EXISTS clause after ALTER + * TABLE part in ALTER TABLE .. DROP statement + */ + if (ropt->if_exists && strncmp(dropStmt, "ALTER TABLE", 11) == 0) { - DropBlobIfExists(AH, te->catalogId.oid); + appendPQExpBufferStr(ftStmt, + "ALTER TABLE IF EXISTS"); + dropStmt = dropStmt + 11; } + + /* + * ALTER TABLE..ALTER COLUMN..DROP DEFAULT does + * not support the IF EXISTS or CASCADE clause, and therefore + * we simply emit the original command for DEFAULT + * objects (modulo the adjustment made above). + * + * Likewise, don't mess with DATABASE PROPERTIES. + * + * If we used CREATE OR REPLACE VIEW as a means of + * quasi-dropping an ON SELECT rule, that should + * be emitted unchanged as well. + * + * For other object types, we need to extract the + * first part of the DROP which includes the + * object type. Most of the time this matches + * te->desc, so search for that; however for the + * different kinds of CONSTRAINTs, we know to + * search for hardcoded "DROP CONSTRAINT" instead. + */ + if (strcmp(te->desc, "DEFAULT") == 0 || + strcmp(te->desc, "DATABASE PROPERTIES") == 0 || + strncmp(dropStmt, "CREATE OR REPLACE VIEW", 22) == 0) + appendPQExpBufferStr(ftStmt, dropStmt); else { - char *dropStmt = pg_strdup(te->dropStmt); - char *dropStmtOrig = dropStmt; - PQExpBuffer ftStmt = createPQExpBuffer(); - - /* - * Need to inject IF EXISTS clause after ALTER - * TABLE part in ALTER TABLE .. DROP statement - */ - if (strncmp(dropStmt, "ALTER TABLE", 11) == 0) + char buffer[40]; + char *mark; + + if (strcmp(te->desc, "CONSTRAINT") == 0 || + strcmp(te->desc, "CHECK CONSTRAINT") == 0 || + strcmp(te->desc, "FK CONSTRAINT") == 0) + strcpy(buffer, "DROP CONSTRAINT"); + else + snprintf(buffer, sizeof(buffer), "DROP %s", + te->desc); + + mark = strstr(dropStmt, buffer); + + if (mark) { - appendPQExpBufferStr(ftStmt, - "ALTER TABLE IF EXISTS"); - dropStmt = dropStmt + 11; + char *name = mark + strlen(buffer); + *mark = '\0'; + /* + * pg_dump always add CASCADE for TYPE with circular dependencies. + * avoid adding duplicated CASCADE. + */ + bool shouldCascade = ropt->drop_cascade && strstr(name, "CASCADE;") == NULL; + char *stmtEnd = strstr(name, ";"); + *stmtEnd = '\0'; + appendPQExpBuffer(ftStmt, "%s%s%s%s%s\n", + dropStmt, buffer, + ropt->if_exists ? " IF EXISTS" : "", + name, + shouldCascade ? " CASCADE;" : ";"); } - - /* - * ALTER TABLE..ALTER COLUMN..DROP DEFAULT does - * not support the IF EXISTS clause, and therefore - * we simply emit the original command for DEFAULT - * objects (modulo the adjustment made above). - * - * Likewise, don't mess with DATABASE PROPERTIES. - * - * If we used CREATE OR REPLACE VIEW as a means of - * quasi-dropping an ON SELECT rule, that should - * be emitted unchanged as well. - * - * For other object types, we need to extract the - * first part of the DROP which includes the - * object type. Most of the time this matches - * te->desc, so search for that; however for the - * different kinds of CONSTRAINTs, we know to - * search for hardcoded "DROP CONSTRAINT" instead. - */ - if (strcmp(te->desc, "DEFAULT") == 0 || - strcmp(te->desc, "DATABASE PROPERTIES") == 0 || - strncmp(dropStmt, "CREATE OR REPLACE VIEW", 22) == 0) - appendPQExpBufferStr(ftStmt, dropStmt); else { - char buffer[40]; - char *mark; - - if (strcmp(te->desc, "CONSTRAINT") == 0 || - strcmp(te->desc, "CHECK CONSTRAINT") == 0 || - strcmp(te->desc, "FK CONSTRAINT") == 0) - strcpy(buffer, "DROP CONSTRAINT"); - else - snprintf(buffer, sizeof(buffer), "DROP %s", - te->desc); - - mark = strstr(dropStmt, buffer); - - if (mark) - { - *mark = '\0'; - appendPQExpBuffer(ftStmt, "%s%s IF EXISTS%s", - dropStmt, buffer, - mark + strlen(buffer)); - } - else - { - /* complain and emit unmodified command */ - pg_log_warning("could not find where to insert IF EXISTS in statement \"%s\"", - dropStmtOrig); - appendPQExpBufferStr(ftStmt, dropStmt); - } + /* complain and emit unmodified command */ + pg_log_warning("could not find where to insert IF EXISTS or CASCADE in statement \"%s\"", + dropStmtOrig); + appendPQExpBufferStr(ftStmt, dropStmt); } - ahprintf(AH, "%s", ftStmt->data); destroyPQExpBuffer(ftStmt); diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index d0ea489614..896f6e7f1e 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -375,6 +375,7 @@ main(int argc, char **argv) {"column-inserts", no_argument, &dopt.column_inserts, 1}, {"disable-dollar-quoting", no_argument, &dopt.disable_dollar_quoting, 1}, {"disable-triggers", no_argument, &dopt.disable_triggers, 1}, + {"drop-cascade", no_argument, &dopt.drop_cascade, 1}, {"enable-row-security", no_argument, &dopt.enable_row_security, 1}, {"exclude-table-data", required_argument, NULL, 4}, {"extra-float-digits", required_argument, NULL, 8}, @@ -677,6 +678,9 @@ main(int argc, char **argv) exit_nicely(1); } + if (dopt.drop_cascade && !dopt.outputClean) + fatal("option --drop-cascade requires option -c/--clean"); + if (dopt.if_exists && !dopt.outputClean) fatal("option --if-exists requires option -c/--clean"); @@ -962,6 +966,7 @@ main(int argc, char **argv) ropt->cparams.pghost = dopt.cparams.pghost ? pg_strdup(dopt.cparams.pghost) : NULL; ropt->cparams.username = dopt.cparams.username ? pg_strdup(dopt.cparams.username) : NULL; ropt->cparams.promptPassword = dopt.cparams.promptPassword; + ropt->drop_cascade = dopt.drop_cascade; ropt->dropSchema = dopt.outputClean; ropt->dataOnly = dopt.dataOnly; ropt->schemaOnly = dopt.schemaOnly; @@ -1063,6 +1068,7 @@ help(const char *progname) printf(_(" --column-inserts dump data as INSERT commands with column names\n")); printf(_(" --disable-dollar-quoting disable dollar quoting, use SQL standard quoting\n")); printf(_(" --disable-triggers disable triggers during data-only restore\n")); + printf(_(" --drop-cascade use CASCADE when dropping objects\n")); printf(_(" --enable-row-security enable row security (dump only content user has\n" " access to)\n")); printf(_(" --exclude-table-data=PATTERN do NOT dump data for the specified table(s)\n")); diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c index 589b4aed53..d4636d5664 100644 --- a/src/bin/pg_dump/pg_restore.c +++ b/src/bin/pg_dump/pg_restore.c @@ -62,6 +62,7 @@ main(int argc, char **argv) Archive *AH; char *inputFileSpec; static int disable_triggers = 0; + static int drop_cascade = 0; static int enable_row_security = 0; static int if_exists = 0; static int no_data_for_failed_tables = 0; @@ -108,6 +109,7 @@ main(int argc, char **argv) * the following options don't have an equivalent short option letter */ {"disable-triggers", no_argument, &disable_triggers, 1}, + {"drop-cascade", no_argument, &drop_cascade, 1}, {"enable-row-security", no_argument, &enable_row_security, 1}, {"if-exists", no_argument, &if_exists, 1}, {"no-data-for-failed-tables", no_argument, &no_data_for_failed_tables, 1}, @@ -368,6 +370,13 @@ main(int argc, char **argv) } opts->disable_triggers = disable_triggers; + + if (drop_cascade && !opts->dropSchema) + { + pg_log_error("option --drop-cascade requires option -c/--clean"); + exit_nicely(1); + } + opts->drop_cascade = drop_cascade; opts->enable_row_security = enable_row_security; opts->noDataForFailedTables = no_data_for_failed_tables; opts->noTablespace = outputNoTablespaces; @@ -491,6 +500,7 @@ usage(const char *progname) printf(_(" -x, --no-privileges skip restoration of access privileges (grant/revoke)\n")); printf(_(" -1, --single-transaction restore as a single transaction\n")); printf(_(" --disable-triggers disable triggers during data-only restore\n")); + printf(_(" --drop-cascade use CASCADE when dropping objects\n")); printf(_(" --enable-row-security enable row security\n")); printf(_(" --if-exists use IF EXISTS when dropping objects\n")); printf(_(" --no-comments do not restore comments\n")); diff --git a/src/bin/pg_dump/t/001_basic.pl b/src/bin/pg_dump/t/001_basic.pl index 083fb3ad08..e5fa4ce013 100644 --- a/src/bin/pg_dump/t/001_basic.pl +++ b/src/bin/pg_dump/t/001_basic.pl @@ -4,7 +4,7 @@ use warnings; use Config; use PostgresNode; use TestLib; -use Test::More tests => 82; +use Test::More tests => 84; my $tempdir = TestLib::tempdir; my $tempdir_short = TestLib::tempdir_short; @@ -93,6 +93,11 @@ command_fails_like( qr/\Qpg_dump: error: option --if-exists requires option -c\/--clean\E/, 'pg_dump: option --if-exists requires option -c/--clean'); +command_fails_like( + [ 'pg_dump', '--drop-cascade' ], + qr/\Qpg_dump: error: option --drop-cascade requires option -c\/--clean\E/, + 'pg_dump: option --drop-cascade requires option -c/--clean'); + command_fails_like( [ 'pg_dump', '-j3' ], qr/\Qpg_dump: error: parallel backup only supported by the directory format\E/, diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl index 86113df29c..1f39dc3c4f 100644 --- a/src/bin/pg_dump/t/002_pg_dump.pl +++ b/src/bin/pg_dump/t/002_pg_dump.pl @@ -73,6 +73,29 @@ my %pgdump_runs = ( 'postgres', ], }, + clean_drop_cascade => { + dump_cmd => [ + 'pg_dump', + '--no-sync', + "--file=$tempdir/clean_drop_cascade.sql", + '-c', + '--drop-cascade', + '--encoding=UTF8', # no-op, just tests that option is accepted + 'postgres', + ], + }, + clean_if_exists_drop_cascade => { + dump_cmd => [ + 'pg_dump', + '--no-sync', + "--file=$tempdir/clean_if_exists_drop_cascade.sql", + '-c', + '--if-exists', + '--drop-cascade', + '--encoding=UTF8', # no-op, just tests that option is accepted + 'postgres', + ], + }, column_inserts => { dump_cmd => [ 'pg_dump', '--no-sync', @@ -386,20 +409,22 @@ my %dump_test_schema_runs = ( # Tests which are considered 'full' dumps by pg_dump, but there # are flags used to exclude specific items (ACLs, blobs, etc). my %full_runs = ( - binary_upgrade => 1, - clean => 1, - clean_if_exists => 1, - createdb => 1, - defaults => 1, - exclude_dump_test_schema => 1, - exclude_test_table => 1, - exclude_test_table_data => 1, - no_blobs => 1, - no_owner => 1, - no_privs => 1, - pg_dumpall_dbprivs => 1, - pg_dumpall_exclude => 1, - schema_only => 1,); + binary_upgrade => 1, + clean => 1, + clean_if_exists => 1, + clean_drop_cascade => 1, + clean_if_exists_drop_cascade => 1, + createdb => 1, + defaults => 1, + exclude_dump_test_schema => 1, + exclude_test_table => 1, + exclude_test_table_data => 1, + no_blobs => 1, + no_owner => 1, + no_privs => 1, + pg_dumpall_dbprivs => 1, + pg_dumpall_exclude => 1, + schema_only => 1,); # This is where the actual tests are defined. my %tests = ( @@ -2676,22 +2701,24 @@ my %tests = ( \QCREATE INDEX measurement_city_id_logdate_idx ON ONLY dump_test.measurement USING\E /xm, like => { - binary_upgrade => 1, - clean => 1, - clean_if_exists => 1, - createdb => 1, - defaults => 1, - exclude_test_table => 1, - exclude_test_table_data => 1, - no_blobs => 1, - no_privs => 1, - no_owner => 1, - only_dump_test_schema => 1, - pg_dumpall_dbprivs => 1, - pg_dumpall_exclude => 1, - schema_only => 1, - section_post_data => 1, - test_schema_plus_blobs => 1, + binary_upgrade => 1, + clean => 1, + clean_if_exists => 1, + clean_drop_cascade => 1, + clean_if_exists_drop_cascade => 1, + createdb => 1, + defaults => 1, + exclude_test_table => 1, + exclude_test_table_data => 1, + no_blobs => 1, + no_privs => 1, + no_owner => 1, + only_dump_test_schema => 1, + pg_dumpall_dbprivs => 1, + pg_dumpall_exclude => 1, + schema_only => 1, + section_post_data => 1, + test_schema_plus_blobs => 1, }, unlike => { exclude_dump_test_schema => 1, @@ -2747,22 +2774,24 @@ my %tests = ( \QALTER INDEX dump_test.measurement_pkey ATTACH PARTITION dump_test_second_schema.measurement_y2006m2_pkey\E /xm, like => { - binary_upgrade => 1, - clean => 1, - clean_if_exists => 1, - createdb => 1, - defaults => 1, - exclude_dump_test_schema => 1, - exclude_test_table => 1, - exclude_test_table_data => 1, - no_blobs => 1, - no_privs => 1, - no_owner => 1, - pg_dumpall_dbprivs => 1, - pg_dumpall_exclude => 1, - role => 1, - schema_only => 1, - section_post_data => 1, + binary_upgrade => 1, + clean => 1, + clean_if_exists => 1, + clean_drop_cascade => 1, + clean_if_exists_drop_cascade => 1, + createdb => 1, + defaults => 1, + exclude_dump_test_schema => 1, + exclude_test_table => 1, + exclude_test_table_data => 1, + no_blobs => 1, + no_privs => 1, + no_owner => 1, + pg_dumpall_dbprivs => 1, + pg_dumpall_exclude => 1, + role => 1, + schema_only => 1, + section_post_data => 1, }, unlike => { only_dump_test_schema => 1, @@ -2904,6 +2933,32 @@ my %tests = ( like => { clean_if_exists => 1, }, }, + 'DROP TYPE int42 CASCADE' => { + regexp => qr/^DROP TYPE dump_test.int42 CASCADE;/m, + like => { clean => 1, clean_drop_cascade => 1 }, + }, + 'DROP FUNCTION trigger_func CASCADE' => { + regexp => qr/^ + \QDROP FUNCTION dump_test.trigger_func() CASCADE;\E + /xm, + like => { clean_drop_cascade => 1, }, + }, + + 'DROP LANGUAGE pltestlang' => { + regexp => qr/^DROP PROCEDURAL LANGUAGE pltestlang CASCADE;/m, + like => { clean_drop_cascade => 1, }, + }, + + 'DROP SCHEMA dump_test' => { + regexp => qr/^DROP SCHEMA dump_test CASCADE;/m, + like => { clean_drop_cascade => 1, }, + }, + + 'DROP TABLE test_table' => { + regexp => qr/^DROP TABLE dump_test\.test_table CASCADE;/m, + like => { clean_drop_cascade => 1, }, + }, + 'DROP ROLE regress_dump_test_role' => { regexp => qr/^ \QDROP ROLE regress_dump_test_role;\E -- 2.31.1