IvorySQL · NotHimmel · Sep 1, 2026
diff --git a/CN/modules/ROOT/nav.adoc b/CN/modules/ROOT/nav.adoc
@@ -1,127 +1,129 @@
-* xref:master/about_ivorysql.adoc[关于IvorySQL]
-** xref:master/welcome.adoc[欢迎]
-** xref:master/release_notes.adoc[发行说明]
-* 快速上手
-** xref:master/getting-started/quick_start.adoc[快速开始]
-* 安装部署
-** xref:master/installation_guide.adoc[安装指南]
-** xref:master/cluster_setup.adoc[集群搭建]
-* Oracle兼容功能
-** xref:master/oracle_compatibility/compat_case_conversion.adoc[1、大小写转换]
-** xref:master/oracle_compatibility/compat_like_operator.adoc[2、LIKE操作符]
-** xref:master/oracle_compatibility/anonymous_block.adoc[3、匿名块]
-** xref:master/oracle_compatibility/compat_function_procedure.adoc[4、函数与存储过程]
-** xref:master/oracle_compatibility/builtin_types_functions.adoc[5、内置数据类型与内置函数]
-** xref:master/oracle_compatibility/port_ip.adoc[6、端口与IP]
-** xref:master/oracle_compatibility/xml_functions.adoc[7、XML函数]
-** xref:master/oracle_compatibility/sequence.adoc[8、sequence]
-** xref:master/oracle_compatibility/package.adoc[9、包]
-** xref:master/oracle_compatibility/invisible_column.adoc[10、不可见列]
-** xref:master/oracle_compatibility/compat_rowid.adoc[11、RowID]
-** xref:master/oracle_compatibility/compat_out_parameter.adoc[12、OUT 参数]
-** xref:master/oracle_compatibility/compat_type_rowtype.adoc[13、%TYPE、%ROWTYPE]
-** xref:master/oracle_compatibility/compat_nls_parameter.adoc[14、NLS 参数]
-** xref:master/oracle_compatibility/compat_force_view.adoc[15、Force View]
-** xref:master/oracle_compatibility/compat_nested_function.adoc[16、嵌套子函数]
-** xref:master/oracle_compatibility/compat_sys_guid.adoc[17、sys_guid 函数]
-** xref:master/oracle_compatibility/compat_empty_string_to_null.adoc[18、空字符串转null]
-** xref:master/oracle_compatibility/compat_call_into.adoc[19、CALL INTO]
-** xref:master/oracle_compatibility/compat_read_only_view.adoc[20、视图只读]
-** xref:master/oracle_compatibility/with_function_procedure.adoc[21、WITH FUNCTION/PROCEDURE]
-** xref:master/oracle_compatibility/compat_create_index_online.adoc[22、索引 ONLINE 参数]
-** xref:master/oracle_compatibility/compat_stragg.adoc[23、STRAGG 函数]
-** xref:master/oracle_compatibility/compat_alter_index_unusable.adoc[24、禁用索引]
-** xref:master/oracle_compatibility/compat_dbtimezone.adoc[25、dbtimezone]
-* 容器化与云服务
-** 容器化指南
-*** xref:master/containerization/k8s_deployment.adoc[K8S部署]
-*** xref:master/containerization/operator_deployment.adoc[Operator部署]
-*** xref:master/containerization/docker_podman_deployment.adoc[Docker & Podman部署]
-*** xref:master/containerization/docker_swarm_compose_deployment.adoc[Docker Swarm & Docker Compose部署]
-** 云服务平台指南
-*** xref:master/cloud_platform/ivorysql_cloud_installation.adoc[IvorySQL Cloud安装]
-*** xref:master/cloud_platform/ivorysql_cloud_usage.adoc[IvorySQL Cloud使用]
-* IvorySQL生态
-** xref:master/cpu_os_adaptation/cpu_architecture_adaptation.adoc[芯片架构适配]
-** xref:master/cpu_os_adaptation/os_architecture_adaptation.adoc[操作系统适配]
-** 生态组件适配
-*** xref:master/ecosystem_components/ecosystem_overview.adoc[概述]
-*** xref:master/ecosystem_components/postgis.adoc[postgis]
-*** xref:master/ecosystem_components/pgvector.adoc[pgvector]
-*** xref:master/ecosystem_components/pgddl.adoc[pgddl(DDL Extractor)]
-*** xref:master/ecosystem_components/pg_cron.adoc[pg_cron]
-*** xref:master/ecosystem_components/pgsql_http.adoc[pgsql-http]
-*** xref:master/ecosystem_components/plpgsql_check.adoc[plpgsql_check]
-*** xref:master/ecosystem_components/pgroonga.adoc[pgroonga]
-*** xref:master/ecosystem_components/pgaudit.adoc[pgaudit]
-*** xref:master/ecosystem_components/pgrouting.adoc[pgrouting]
-*** xref:master/ecosystem_components/system_stats.adoc[system_stats]
-*** xref:master/ecosystem_components/wal2json.adoc[wal2json]
-*** xref:master/ecosystem_components/pg_stat_monitor.adoc[pg_stat_monitor]
-*** xref:master/ecosystem_components/pg_ai_query.adoc[pg_ai_query]
-*** xref:master/ecosystem_components/pg_partman.adoc[pg_partman]
-*** xref:master/ecosystem_components/pgbouncer.adoc[pgbouncer]
-*** xref:master/ecosystem_components/age.adoc[age]
-*** xref:master/ecosystem_components/pg_curl.adoc[pg_curl]
-*** xref:master/ecosystem_components/pg_textsearch.adoc[pg_textsearch]
-*** xref:master/ecosystem_components/pg_hint_plan.adoc[pg_hint_plan]
-*** xref:master/ecosystem_components/redis_fdw.adoc[redis_fdw]
-*** xref:master/ecosystem_components/pg_show_plans.adoc[pg_show_plans]
-*** xref:master/ecosystem_components/pg_bulkload.adoc[pg_bulkload]
-*** xref:master/ecosystem_components/pg_bigm.adoc[pg_bigm]
-*** xref:master/ecosystem_components/pg_profile.adoc[pg_profile]
-*** xref:master/ecosystem_components/pg_repack.adoc[pg_repack]
-*** xref:master/ecosystem_components/pgdog.adoc[PgDog]
-*** xref:master/ecosystem_components/pg_readonly.adoc[pg_readonly]
-*** xref:master/ecosystem_components/zhparser.adoc[zhparser]
-*** xref:master/ecosystem_components/pgbackrest.adoc[pgBackRest]
-*** xref:master/ecosystem_components/set_user.adoc[set_user]
-* 监控运维
-** xref:master/getting-started/daily_monitoring.adoc[日常监控]
-** xref:master/getting-started/daily_maintenance.adoc[日常维护]
-** xref:master/operation_guide.adoc[运维管理指南]
-* 数据迁移
-** xref:master/migration_guide.adoc[迁移指南]
-* IvorySQL开发者
-** xref:master/contribution/contribution_guide.adoc[贡献指南]
-** xref:master/developer_guide.adoc[开发者指南]
-** IvorySQL架构设计
-*** 查询处理
-**** xref:master/architecture/dual_parser.adoc[双parser]
-*** 兼容框架
-**** xref:master/architecture/framework_design.adoc[框架设计]
-**** xref:master/architecture/guc_framework.adoc[GUC框架]
-**** xref:master/architecture/dual_mode_design.adoc[双模式设计]
-**** xref:master/architecture/initdb_process.adoc[initdb过程]
-*** 兼容特性
-**** xref:master/compatibility_features_design/like_operator.adoc[like]
-**** xref:master/compatibility_features_design/rowid.adoc[RowID]
-**** xref:master/compatibility_features_design/out_parameter.adoc[OUT 参数]
-**** xref:master/compatibility_features_design/type_rowtype.adoc[%TYPE、%ROWTYPE]
-**** xref:master/compatibility_features_design/nls_parameter.adoc[NLS 参数]
-**** xref:master/compatibility_features_design/function_procedure.adoc[函数与存储过程]
-**** xref:master/compatibility_features_design/nested_function.adoc[嵌套子函数]
-**** xref:master/compatibility_features_design/force_view.adoc[Force View]
-**** xref:master/compatibility_features_design/case_conversion.adoc[大小写转换]
-**** xref:master/compatibility_features_design/sys_guid_function.adoc[sys_guid 函数]
-**** xref:master/compatibility_features_design/empty_string_to_null.adoc[空字符串转null]
-**** xref:master/compatibility_features_design/call_into.adoc[CALL INTO]
-**** xref:master/compatibility_features_design/read_only_view.adoc[视图只读]
-**** xref:master/compatibility_features_design/with_function_procedure_impl.adoc[WITH FUNCTION/PROCEDURE]
-**** xref:master/compatibility_features_design/create_index_online.adoc[索引 ONLINE 参数]
-**** xref:master/compatibility_features_design/alter_index_unusable_impl.adoc[禁用索引]
-*** 内置函数
-**** xref:master/oracle_builtin_functions/sys_context.adoc[sys_context]
-**** xref:master/oracle_builtin_functions/userenv.adoc[userenv]
-**** xref:master/oracle_builtin_functions/rawtohex.adoc[rawtohex]
-**** xref:master/oracle_builtin_functions/stragg.adoc[stragg]
-**** xref:master/oracle_builtin_functions/dbtimezone_impl.adoc[dbtimezone]
-*** xref:master/gb18030.adoc[国标GB18030]
-* 参考指南
-** xref:master/tools_reference.adoc[工具参考]
-** xref:master/contribution/asciidoc_syntax_reference.adoc[asciidoc语法快速参考]
-** xref:master/pg_reference/pg_parameters_reference.adoc[PG参数参考手册]
-** xref:master/pg_reference/pg_functions_reference.adoc[PG函数参考手册]
-* 常见问题解答
-** xref:master/contribution/faq.adoc[FAQ]
-
+* xref:master/about_ivorysql.adoc[关于IvorySQL]
+** xref:master/welcome.adoc[欢迎]
+** xref:master/release_notes.adoc[发行说明]
+* 快速上手
+** xref:master/getting-started/quick_start.adoc[快速开始]
+* 安装部署
+** xref:master/installation_guide.adoc[安装指南]
+** xref:master/cluster_setup.adoc[集群搭建]
+* Oracle兼容功能
+** xref:master/oracle_compatibility/compat_case_conversion.adoc[1、大小写转换]
+** xref:master/oracle_compatibility/compat_like_operator.adoc[2、LIKE操作符]
+** xref:master/oracle_compatibility/anonymous_block.adoc[3、匿名块]
+** xref:master/oracle_compatibility/compat_function_procedure.adoc[4、函数与存储过程]
+** xref:master/oracle_compatibility/builtin_types_functions.adoc[5、内置数据类型与内置函数]
+** xref:master/oracle_compatibility/port_ip.adoc[6、端口与IP]
+** xref:master/oracle_compatibility/xml_functions.adoc[7、XML函数]
+** xref:master/oracle_compatibility/sequence.adoc[8、sequence]
+** xref:master/oracle_compatibility/package.adoc[9、包]
+** xref:master/oracle_compatibility/invisible_column.adoc[10、不可见列]
+** xref:master/oracle_compatibility/compat_rowid.adoc[11、RowID]
+** xref:master/oracle_compatibility/compat_out_parameter.adoc[12、OUT 参数]
+** xref:master/oracle_compatibility/compat_type_rowtype.adoc[13、%TYPE、%ROWTYPE]
+** xref:master/oracle_compatibility/compat_nls_parameter.adoc[14、NLS 参数]
+** xref:master/oracle_compatibility/compat_force_view.adoc[15、Force View]
+** xref:master/oracle_compatibility/compat_nested_function.adoc[16、嵌套子函数]
+** xref:master/oracle_compatibility/compat_sys_guid.adoc[17、sys_guid 函数]
+** xref:master/oracle_compatibility/compat_empty_string_to_null.adoc[18、空字符串转null]
+** xref:master/oracle_compatibility/compat_call_into.adoc[19、CALL INTO]
+** xref:master/oracle_compatibility/compat_read_only_view.adoc[20、视图只读]
+** xref:master/oracle_compatibility/with_function_procedure.adoc[21、WITH FUNCTION/PROCEDURE]
+** xref:master/oracle_compatibility/compat_create_index_online.adoc[22、索引 ONLINE 参数]
+** xref:master/oracle_compatibility/compat_stragg.adoc[23、STRAGG 函数]
+** xref:master/oracle_compatibility/compat_alter_index_unusable.adoc[24、禁用索引]
+** xref:master/oracle_compatibility/compat_dbtimezone.adoc[25、dbtimezone]
+** xref:master/oracle_compatibility/compat_lnnvl.adoc[26、LNNVL 函数]
+* 容器化与云服务
+** 容器化指南
+*** xref:master/containerization/k8s_deployment.adoc[K8S部署]
+*** xref:master/containerization/operator_deployment.adoc[Operator部署]
+*** xref:master/containerization/docker_podman_deployment.adoc[Docker & Podman部署]
+*** xref:master/containerization/docker_swarm_compose_deployment.adoc[Docker Swarm & Docker Compose部署]
+** 云服务平台指南
+*** xref:master/cloud_platform/ivorysql_cloud_installation.adoc[IvorySQL Cloud安装]
+*** xref:master/cloud_platform/ivorysql_cloud_usage.adoc[IvorySQL Cloud使用]
+* IvorySQL生态
+** xref:master/cpu_os_adaptation/cpu_architecture_adaptation.adoc[芯片架构适配]
+** xref:master/cpu_os_adaptation/os_architecture_adaptation.adoc[操作系统适配]
+** 生态组件适配
+*** xref:master/ecosystem_components/ecosystem_overview.adoc[概述]
+*** xref:master/ecosystem_components/postgis.adoc[postgis]
+*** xref:master/ecosystem_components/pgvector.adoc[pgvector]
+*** xref:master/ecosystem_components/pgddl.adoc[pgddl(DDL Extractor)]
+*** xref:master/ecosystem_components/pg_cron.adoc[pg_cron]
+*** xref:master/ecosystem_components/pgsql_http.adoc[pgsql-http]
+*** xref:master/ecosystem_components/plpgsql_check.adoc[plpgsql_check]
+*** xref:master/ecosystem_components/pgroonga.adoc[pgroonga]
+*** xref:master/ecosystem_components/pgaudit.adoc[pgaudit]
+*** xref:master/ecosystem_components/pgrouting.adoc[pgrouting]
+*** xref:master/ecosystem_components/system_stats.adoc[system_stats]
+*** xref:master/ecosystem_components/wal2json.adoc[wal2json]
+*** xref:master/ecosystem_components/pg_stat_monitor.adoc[pg_stat_monitor]
+*** xref:master/ecosystem_components/pg_ai_query.adoc[pg_ai_query]
+*** xref:master/ecosystem_components/pg_partman.adoc[pg_partman]
+*** xref:master/ecosystem_components/pgbouncer.adoc[pgbouncer]
+*** xref:master/ecosystem_components/age.adoc[age]
+*** xref:master/ecosystem_components/pg_curl.adoc[pg_curl]
+*** xref:master/ecosystem_components/pg_textsearch.adoc[pg_textsearch]
+*** xref:master/ecosystem_components/pg_hint_plan.adoc[pg_hint_plan]
+*** xref:master/ecosystem_components/redis_fdw.adoc[redis_fdw]
+*** xref:master/ecosystem_components/pg_show_plans.adoc[pg_show_plans]
+*** xref:master/ecosystem_components/pg_bulkload.adoc[pg_bulkload]
+*** xref:master/ecosystem_components/pg_bigm.adoc[pg_bigm]
+*** xref:master/ecosystem_components/pg_profile.adoc[pg_profile]
+*** xref:master/ecosystem_components/pg_repack.adoc[pg_repack]
+*** xref:master/ecosystem_components/pgdog.adoc[PgDog]
+*** xref:master/ecosystem_components/pg_readonly.adoc[pg_readonly]
+*** xref:master/ecosystem_components/zhparser.adoc[zhparser]
+*** xref:master/ecosystem_components/pgbackrest.adoc[pgBackRest]
+*** xref:master/ecosystem_components/set_user.adoc[set_user]
+* 监控运维
+** xref:master/getting-started/daily_monitoring.adoc[日常监控]
+** xref:master/getting-started/daily_maintenance.adoc[日常维护]
+** xref:master/operation_guide.adoc[运维管理指南]
+* 数据迁移
+** xref:master/migration_guide.adoc[迁移指南]
+* IvorySQL开发者
+** xref:master/contribution/contribution_guide.adoc[贡献指南]
+** xref:master/developer_guide.adoc[开发者指南]
+** IvorySQL架构设计
+*** 查询处理
+**** xref:master/architecture/dual_parser.adoc[双parser]
+*** 兼容框架
+**** xref:master/architecture/framework_design.adoc[框架设计]
+**** xref:master/architecture/guc_framework.adoc[GUC框架]
+**** xref:master/architecture/dual_mode_design.adoc[双模式设计]
+**** xref:master/architecture/initdb_process.adoc[initdb过程]
+*** 兼容特性
+**** xref:master/compatibility_features_design/like_operator.adoc[like]
+**** xref:master/compatibility_features_design/rowid.adoc[RowID]
+**** xref:master/compatibility_features_design/out_parameter.adoc[OUT 参数]
+**** xref:master/compatibility_features_design/type_rowtype.adoc[%TYPE、%ROWTYPE]
+**** xref:master/compatibility_features_design/nls_parameter.adoc[NLS 参数]
+**** xref:master/compatibility_features_design/function_procedure.adoc[函数与存储过程]
+**** xref:master/compatibility_features_design/nested_function.adoc[嵌套子函数]
+**** xref:master/compatibility_features_design/force_view.adoc[Force View]
+**** xref:master/compatibility_features_design/case_conversion.adoc[大小写转换]
+**** xref:master/compatibility_features_design/sys_guid_function.adoc[sys_guid 函数]
+**** xref:master/compatibility_features_design/empty_string_to_null.adoc[空字符串转null]
+**** xref:master/compatibility_features_design/call_into.adoc[CALL INTO]
+**** xref:master/compatibility_features_design/read_only_view.adoc[视图只读]
+**** xref:master/compatibility_features_design/with_function_procedure_impl.adoc[WITH FUNCTION/PROCEDURE]
+**** xref:master/compatibility_features_design/create_index_online.adoc[索引 ONLINE 参数]
+**** xref:master/compatibility_features_design/alter_index_unusable_impl.adoc[禁用索引]
+*** 内置函数
+**** xref:master/oracle_builtin_functions/sys_context.adoc[sys_context]
+**** xref:master/oracle_builtin_functions/userenv.adoc[userenv]
+**** xref:master/oracle_builtin_functions/rawtohex.adoc[rawtohex]
+**** xref:master/oracle_builtin_functions/stragg.adoc[stragg]
+**** xref:master/oracle_builtin_functions/dbtimezone_impl.adoc[dbtimezone]
+**** xref:master/oracle_builtin_functions/lnnvl.adoc[lnnvl]
+*** xref:master/gb18030.adoc[国标GB18030]
+* 参考指南
+** xref:master/tools_reference.adoc[工具参考]
+** xref:master/contribution/asciidoc_syntax_reference.adoc[asciidoc语法快速参考]
+** xref:master/pg_reference/pg_parameters_reference.adoc[PG参数参考手册]
+** xref:master/pg_reference/pg_functions_reference.adoc[PG函数参考手册]
+* 常见问题解答
+** xref:master/contribution/faq.adoc[FAQ]
+
diff --git a/CN/modules/ROOT/pages/master/oracle_builtin_functions/lnnvl.adoc b/CN/modules/ROOT/pages/master/oracle_builtin_functions/lnnvl.adoc
@@ -0,0 +1,131 @@
+:sectnums:
+:sectnumlevels: 5
+
+:imagesdir: ./_images
+
+= LNNVL 函数的实现
+
+== 目的
+
+IvorySQL 在 `contrib/ivorysql_ora` 扩展中新增 `sys.lnnvl(boolean)` 函数，
+实现与 Oracle 同名函数一致的条件取反行为：条件求值为 FALSE 或 UNKNOWN 时返回 TRUE，
+求值为 TRUE 时返回 FALSE。
+
+== 实现说明
+
+=== 语义等价于 IS NOT TRUE
+
+LNNVL 的真值表与 SQL 标准的 `IS NOT TRUE` 谓词逐格相同：
+
+[cols="1,1,1"]
+|===
+|条件求值结果 |`LNNVL(cond)` |`cond IS NOT TRUE`
+
+|TRUE
+|FALSE
+|FALSE
+
+|FALSE
+|TRUE
+|TRUE
+
+|UNKNOWN
+|TRUE
+|TRUE
+|===
+
+因此实现无需新增任何求值逻辑，函数体只是这一个谓词。
+PostgreSQL 中 `IS NOT TRUE` 的求值位于
+`src/backend/executor/execExprInterp.c` 的 `EEOP_BOOLTEST_IS_NOT_TRUE` 分支，
+入参为 NULL 时直接返回 true 并清除结果的 null 标记，
+因此 LNNVL 自身永不返回 NULL。
+
+=== SQL 定义
+
+函数定义位于
+`contrib/ivorysql_ora/src/builtin_functions/builtin_functions--1.0.sql`。
+
+[source,sql]
+----
+CREATE FUNCTION sys.lnnvl(pg_catalog.bool)
+RETURNS pg_catalog.bool
+AS $$SELECT $1 IS NOT TRUE$$
+LANGUAGE sql
+CALLED ON NULL INPUT
+PARALLEL SAFE
+IMMUTABLE;
+----
+
+各项属性的选择理由：
+
+[cols="1,1,3"]
+|===
+|属性 |取值 |理由
+
+|所在模式
+|`sys`
+|与其它 Oracle 兼容函数一致。`sys` 仅在 Oracle 兼容模式下进入隐式 `search_path`。
+
+|参数类型
+|`pg_catalog.bool`
+|显式限定模式，避免 Oracle 模式下 `sys` 位于 `search_path` 首位时类型名解析受影响。
+
+|语言
+|`sql`
+|可被 `inline_function()` 内联，见下节。C 函数不会被内联。
+
+|NULL 处理
+|`CALLED ON NULL INPUT`
+|必须项，见下节。
+
+|易变性
+|`IMMUTABLE`
+|纯逻辑运算，同一输入恒定输出；也是用于表达式索引等场景的前提。
+
+|并行性
+|`PARALLEL SAFE`
+|无副作用。若不声明，默认为 `PARALLEL UNSAFE`，会禁用相关查询的并行计划。
+|===
+
+=== CALLED ON NULL INPUT 是必须项
+
+`CALLED ON NULL INPUT` 是 SQL 的默认值，此处显式写出是为了防止被误改。
+
+若声明为 `STRICT`，入参为 NULL 时函数体根本不会执行，直接返回 NULL，
+而正确行为是返回 TRUE —— 恰好毁掉 LNNVL 存在的唯一理由，且不产生任何错误。
+风险来自代码风格的一致性压力：`builtin_functions--1.0.sql` 中多数邻近函数均声明为
+`STRICT`，按邻居样式统一即会踩中。
+
+`STRICT` 还会连带废掉内联。声明为严格意味着承诺"NULL 进则 NULL 出"，
+而 `IS NOT TRUE` 本身并非严格谓词，优化器无法在保持语义的前提下将其展开，
+只能保留函数调用：
+
+[source,text]
+----
+-- CALLED ON NULL INPUT
+Filter: (t.v IS NOT TRUE)
+
+-- STRICT
+Filter: f_strict(t.v)
+----
+
+因此误写为 `STRICT` 是双重损失：语义错误且静默，同时性能退化为逐行函数调用。
+
+=== 函数内联
+
+函数体是可内联的简单 SQL 表达式，优化器的 `inline_function()` 会将其折叠到调用处：
+
+[source,sql]
+----
+EXPLAIN (VERBOSE, COSTS OFF) SELECT id FROM t WHERE LNNVL(v >= 0.2);
+----
+
+[source,text]
+----
+ Seq Scan on public.t
+   Output: id
+   Filter: ((t.v >= 0.2) IS NOT TRUE)
+----
+
+计划中已不存在函数调用，与用户直接书写 `IS NOT TRUE` 的计划逐字相同，
+因此不引入额外运行期开销。