1.mybatis-plus自定义处理类型无效

场景：自定义与jdbc的数据类型映射，无效。代码如下：

@MappedTypes(JSONArray.class)
@MappedJdbcTypes(JdbcType.VARCHAR)
public class JSONArrayHandler extends BaseTypeHandler<JSONArray> {
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, JSONArray parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, String.valueOf(parameter.toJSONString()));
    }
    @Override
    public JSONArray getNullableResult(ResultSet rs, String columnName) throws SQLException {
        String sqlJson = rs.getString(columnName);
        if (null != sqlJson){
            return JSONArray.parseArray(sqlJson);
        }
        return null;
    }
    @Override
    public JSONArray getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        String sqlJson = rs.getString(columnIndex);
        if (null != sqlJson){
            return JSONArray.parseArray(sqlJson);
        }
        return null;
    }
    @Override
    public JSONArray getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        String sqlJson = cs.getString(columnIndex);
        if (null != sqlJson){
            return JSONArray.parseArray(sqlJson);
        }
        return null;
    }
}

@Data
@Accessors(chain = true)
@TableName(value = "t_third_product", autoResultMap = true)
@EqualsAndHashCode(callSuper = true)
public class TThirdProduct extends BaseTaskEntity {
    /**
     * 第三方商品id
     */
    private String thirdProductId;
    /**
     * 规格
     */
    @TableField(typeHandler = JSONArrayHandler.class)
    private JSONArray specifications;
    @TableField(typeHandler = JSONArrayHandler.class)
    private JSONArray dimensions;
    @TableField(typeHandler = JSONArrayHandler.class)
    private JSONArray imagesCopyright;
}

异常：

解决方法:

https://www.jb51.net/article/204841.htm

2.查看慢sql

select * from pg_stat_activity where state<>'idle' and now()-query_start > interval '1 s' order by query_start;

3.查看占用连接数

select count( * ) from pg_stat_activity where state not like '%idle';

4.查看最耗时的sql

select * from pg_stat_statements order by total_time desc limit 5;

5.全表扫描频次最高的sql

select * from pg_stat_user_tables where n_live_tup > 100000 and seq_scan > 0 order by seq_tup_read desc limit 10;