oracle 插入语句奇怪性能有关问题

oracle 插入语句奇怪性能问题
异常语句：
insert into t_i18n values('com.huawei.support.enterprise.web.page.mySpace.Halp.trainingBackList','zh','返回',sysdate,'test1');
执行插入时一直没有响应
改为：insert into t_i18n values('com.huawei.support.enterprise.web.page.mySpace.Halp.trainingBack','zh','返回',sysdate,'test1');
即可插入

表结构：
-- Create table
create table T_I18N
(
  KEY              VARCHAR2(1000) not null,
  LANG             VARCHAR2(10) not null,
  CONTENT          VARCHAR2(4000) not null,
  LAST_UPDATE_TIME DATE not null,
  LAST_UPDATE_BY   VARCHAR2(100) not null
)
tablespace SUPPORTE
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 256
    next 1
    minextents 1
    maxextents unlimited
  );
-- Create/Recreate primary, unique and foreign key constraints
alter table T_I18N
  add constraint UN_I18N unique (KEY, LANG)
  using index
  tablespace SUPPORTE
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 192K
    next 1M
    minextents 1
    maxextents unlimited
  );
-- Create/Recreate indexes
create index IDX_T_I18N_KEY on T_I18N (KEY)
  tablespace SUPPORTE
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 192K
    next 1M
    minextents 1
    maxextents unlimited
  );
create index IDX_T_I18N_LANG on T_I18N (LANG)
  tablespace SUPPORTE
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 128K
    next 1M
    minextents 1
    maxextents unlimited
  );
create index IDX_T_LAST_UPDATE_TIME on T_I18N (LAST_UPDATE_TIME)
  tablespace SUPPORTE
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 128K
    next 1M
    minextents 1
    maxextents unlimited
  );
异常问题未知；以此标记