maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Monty!

On Apr 19, Michael Widenius wrote:
> revision-id: 6b06a99e4a4 (mariadb-10.5.2-557-g6b06a99e4a4)
> parent(s): 9c1e36696f3
> author: Michael Widenius <michael.widenius@xxxxxxxxx>
> committer: Michael Widenius <michael.widenius@xxxxxxxxx>
> timestamp: 2021-03-25 12:06:34 +0200
> message:
> 
> Avoid creating the .frm file twice in some cases
>
> diff --git a/sql/handler.cc b/sql/handler.cc
> index c286aef3a9e..fe2fe6e9426 100644
> --- a/sql/handler.cc
> +++ b/sql/handler.cc
> @@ -5536,8 +5536,9 @@ int ha_create_table(THD *thd, const char *path,
>  
>    if (frm)
>    {
> -    bool write_frm_now= !create_info->db_type->discover_table &&
> -                        !create_info->tmp_table();
> +    bool write_frm_now= (!create_info->db_type->discover_table &&
> +                         !create_info->tmp_table() &&
> +                         !create_info->frm_is_created);

Is this the real problem? frm created twice?
Why ha_create_table() is invoked twice at all?

>  
>      share.frm_image= frm;
>  
> diff --git a/sql/sql_table.cc b/sql/sql_table.cc
> index e00d3ee1ed2..73642a5bd97 100644
> --- a/sql/sql_table.cc
> +++ b/sql/sql_table.cc
> @@ -547,8 +547,13 @@ uint build_table_filename(char *buff, size_t bufflen, const char *db,
>  
>    (void) tablename_to_filename(db, dbbuff, sizeof(dbbuff));
>  
> -  /* Check if this is a temporary table name. Allow it if a corresponding .frm file exists */
> -  if (is_prefix(table_name, tmp_file_prefix) && strlen(table_name) < NAME_CHAR_LEN &&
> +  /*
> +    Check if this is a temporary table name. Allow it if a corresponding .frm
> +    file exists.
> +  */
> +  if (!(flags & FN_IS_TMP) &&
> +      is_prefix(table_name, tmp_file_prefix) &&
> +      strlen(table_name) < NAME_CHAR_LEN &&

good idea!

>        check_if_frm_exists(tbbuff, dbbuff, table_name))
>      flags|= FN_IS_TMP;
>  
> @@ -9817,7 +9827,7 @@ do_continue:;
>  
>    if (table->s->tmp_table != NO_TMP_TABLE)
>    {
> -    /* Close lock if this is a transactional table */
> +    /* Unlock lock if this is a transactional temporary table */

strictly speaking, you don't "unlock lock",
you "unlock a resource" (e.g. a table)
or you "release a lock"

>      if (thd->lock)
>      {
>        if (thd->locked_tables_mode != LTM_LOCK_TABLES &&

Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx