From c851e3d68993feac2f35c101e8ed244ffd6b0935 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, pg_dumpall 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_dumpall.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 | 152 ++++++++++++++------------- src/bin/pg_dump/pg_dump.c | 6 ++ src/bin/pg_dump/pg_dumpall.c | 11 ++ src/bin/pg_dump/pg_restore.c | 10 ++ 8 files changed, 138 insertions(+), 73 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_dumpall.sgml b/doc/src/sgml/ref/pg_dumpall.sgml index 3c2f9c774f..fc5742b461 100644 --- a/doc/src/sgml/ref/pg_dumpall.sgml +++ b/doc/src/sgml/ref/pg_dumpall.sgml @@ -289,6 +289,16 @@ 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..cb3e9b839c 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; @@ -528,100 +529,105 @@ 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(); + char buffer[40]; + char *mark; - /* - * Need to inject IF EXISTS clause after ALTER - * TABLE part in ALTER TABLE .. DROP statement - */ - if (strncmp(dropStmt, "ALTER TABLE", 11) == 0) + 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 *stmtEnd; + *mark = '\0'; + stmtEnd = strstr(mark + strlen(buffer), ";"); + *stmtEnd = '\0'; + appendPQExpBuffer(ftStmt, "%s%s %s%s%s%s", + dropStmt, buffer, + ropt->if_exists ? "IF EXISTS" : "", + mark + strlen(buffer), + ropt->drop_cascade ? " CASCADE;" : ";", + stmtEnd + 1); } - - /* - * 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); pg_free(dropStmtOrig); } + } } } 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_dumpall.c b/src/bin/pg_dump/pg_dumpall.c index 007a3d0f9a..4602e196bb 100644 --- a/src/bin/pg_dump/pg_dumpall.c +++ b/src/bin/pg_dump/pg_dumpall.c @@ -69,6 +69,7 @@ static int binary_upgrade = 0; static int column_inserts = 0; static int disable_dollar_quoting = 0; static int disable_triggers = 0; +static int drop_cascade = 0; static int if_exists = 0; static int inserts = 0; static int no_tablespaces = 0; @@ -128,6 +129,7 @@ main(int argc, char *argv[]) {"column-inserts", no_argument, &column_inserts, 1}, {"disable-dollar-quoting", no_argument, &disable_dollar_quoting, 1}, {"disable-triggers", no_argument, &disable_triggers, 1}, + {"drop-cascade", no_argument, &drop_cascade, 1}, {"exclude-database", required_argument, NULL, 6}, {"extra-float-digits", required_argument, NULL, 5}, {"if-exists", no_argument, &if_exists, 1}, @@ -360,6 +362,12 @@ main(int argc, char *argv[]) exit_nicely(1); } + if (drop_cascade && !output_clean) + { + pg_log_error("option --drop-cascade requires option -c/--clean"); + exit_nicely(1); + } + /* Make sure the user hasn't specified a mix of globals-only options */ if (globals_only && roles_only) { @@ -410,6 +418,8 @@ main(int argc, char *argv[]) appendPQExpBufferStr(pgdumpopts, " --disable-dollar-quoting"); if (disable_triggers) appendPQExpBufferStr(pgdumpopts, " --disable-triggers"); + if (drop_cascade) + appendPQExpBufferStr(pgdumpopts, " --drop-cascade"); if (inserts) appendPQExpBufferStr(pgdumpopts, " --inserts"); if (no_tablespaces) @@ -639,6 +649,7 @@ help(void) 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(_(" --exclude-database=PATTERN exclude databases whose name matches PATTERN\n")); printf(_(" --extra-float-digits=NUM override default setting for extra_float_digits\n")); printf(_(" --if-exists use IF EXISTS when dropping objects\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")); -- 2.29.2