Re: Audit Table storage for Primary Key(s)
On 30-05-2013 09:27, Neil Tompkins wrote: Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil First you need to ask yourself how you expect to use the table in the future. Will you be looking up the data on a regular basis? Or will lookups only be something you will do in exceptional situtions? What is the intended goal of having a UUID for the primary key rather than, say, an integer - or having no PK at all? My immediate thought when reading this was why even store that data in a table? - if it's a simple log, use a log file. Especially if you don't know how you intend to search for data later on. There are many tools that are far superior to SQL when it comes to searching for text strings. You could even consider having a CSV table, which will give you an SQL interface to said text file. / Carsten -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Audit Table storage for Primary Key(s)
Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I use UUID because we have currently 54 tables, of which probably 30 will be audited. So a INT PK wouldn't work because of the number of updates we are applying. On Fri, May 31, 2013 at 9:58 AM, Carsten Pedersen cars...@bitbybit.dkwrote: On 30-05-2013 09:27, Neil Tompkins wrote: Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil First you need to ask yourself how you expect to use the table in the future. Will you be looking up the data on a regular basis? Or will lookups only be something you will do in exceptional situtions? What is the intended goal of having a UUID for the primary key rather than, say, an integer - or having no PK at all? My immediate thought when reading this was why even store that data in a table? - if it's a simple log, use a log file. Especially if you don't know how you intend to search for data later on. There are many tools that are far superior to SQL when it comes to searching for text strings. You could even consider having a CSV table, which will give you an SQL interface to said text file. / Carsten -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Audit Table storage for Primary Key(s)
Again: Unless you can give some idea as to the kind of lookups you will be performing (which fields? Temporal values? etc.), it is impossible to give advice on the table structure. I wouldn't blame anyone for not being able to do so; saving data for debugging will always be a moving target and almost by definition you don't know today what you'll be looking for tomorrow. That's why I think that using CSV tables _the contents of which can subsequently be analyzed using any of a number of text file processing tools_ may indeed be your best initial option. On UUIDs vs. INTs: (1) Please do yourself a favor and read up on how UUIDs are generated. If it's the same server that generates all the UUIDs, you won't get a lot of uniqueness for the amount of space you'll be using for your data and index; (2) Please do the math of just how many inserts you can do per second over the next 1.000 years if you use a longint auto-increment field for your PK. / Carsten On 31-05-2013 11:14, Neil Tompkins wrote: Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I use UUID because we have currently 54 tables, of which probably 30 will be audited. So a INT PK wouldn't work because of the number of updates we are applying. On Fri, May 31, 2013 at 9:58 AM, Carsten Pedersen cars...@bitbybit.dkwrote: On 30-05-2013 09:27, Neil Tompkins wrote: Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil First you need to ask yourself how you expect to use the table in the future. Will you be looking up the data on a regular basis? Or will lookups only be something you will do in exceptional situtions? What is the intended goal of having a UUID for the primary key rather than, say, an integer - or having no PK at all? My immediate thought when reading this was why even store that data in a table? - if it's a simple log, use a log file. Especially if you don't know how you intend to search for data later on. There are many tools that are far superior to SQL when it comes to searching for text strings. You could even consider having a CSV table, which will give you an SQL interface to said text file. / Carsten -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Audit Table storage for Primary Key(s)
The kind of look ups will be trying to diagnose when and by who applied a update. So the primary key of the audit is important. My question is for performance, should the primary key be stored as a indexed field like I mentioned before, or should I have a actual individual field per primary key On Fri, May 31, 2013 at 11:03 AM, Carsten Pedersen cars...@bitbybit.dkwrote: Again: Unless you can give some idea as to the kind of lookups you will be performing (which fields? Temporal values? etc.), it is impossible to give advice on the table structure. I wouldn't blame anyone for not being able to do so; saving data for debugging will always be a moving target and almost by definition you don't know today what you'll be looking for tomorrow. That's why I think that using CSV tables _the contents of which can subsequently be analyzed using any of a number of text file processing tools_ may indeed be your best initial option. On UUIDs vs. INTs: (1) Please do yourself a favor and read up on how UUIDs are generated. If it's the same server that generates all the UUIDs, you won't get a lot of uniqueness for the amount of space you'll be using for your data and index; (2) Please do the math of just how many inserts you can do per second over the next 1.000 years if you use a longint auto-increment field for your PK. / Carsten On 31-05-2013 11:14, Neil Tompkins wrote: Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I use UUID because we have currently 54 tables, of which probably 30 will be audited. So a INT PK wouldn't work because of the number of updates we are applying. On Fri, May 31, 2013 at 9:58 AM, Carsten Pedersen cars...@bitbybit.dk wrote: On 30-05-2013 09:27, Neil Tompkins wrote: Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil First you need to ask yourself how you expect to use the table in the future. Will you be looking up the data on a regular basis? Or will lookups only be something you will do in exceptional situtions? What is the intended goal of having a UUID for the primary key rather than, say, an integer - or having no PK at all? My immediate thought when reading this was why even store that data in a table? - if it's a simple log, use a log file. Especially if you don't know how you intend to search for data later on. There are many tools that are far superior to SQL when it comes to searching for text strings. You could even consider having a CSV table, which will give you an SQL interface to said text file. / Carsten -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Audit Table storage for Primary Key(s)
Based on the little information available, I would make a lookup field consisting of tablename and primary keys. (although I still believe that storing this information in the database in the first place is probably the wrong approach, but to each his own) / Carsten On 31-05-2013 12:58, Neil Tompkins wrote: The kind of look ups will be trying to diagnose when and by who applied a update. So the primary key of the audit is important. My question is for performance, should the primary key be stored as a indexed field like I mentioned before, or should I have a actual individual field per primary key On Fri, May 31, 2013 at 11:03 AM, Carsten Pedersen cars...@bitbybit.dk mailto:cars...@bitbybit.dk wrote: Again: Unless you can give some idea as to the kind of lookups you will be performing (which fields? Temporal values? etc.), it is impossible to give advice on the table structure. I wouldn't blame anyone for not being able to do so; saving data for debugging will always be a moving target and almost by definition you don't know today what you'll be looking for tomorrow. That's why I think that using CSV tables _the contents of which can subsequently be analyzed using any of a number of text file processing tools_ may indeed be your best initial option. On UUIDs vs. INTs: (1) Please do yourself a favor and read up on how UUIDs are generated. If it's the same server that generates all the UUIDs, you won't get a lot of uniqueness for the amount of space you'll be using for your data and index; (2) Please do the math of just how many inserts you can do per second over the next 1.000 years if you use a longint auto-increment field for your PK. / Carsten On 31-05-2013 11 tel:31-05-2013%2011:14, Neil Tompkins wrote: Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I use UUID because we have currently 54 tables, of which probably 30 will be audited. So a INT PK wouldn't work because of the number of updates we are applying. On Fri, May 31, 2013 at 9:58 AM, Carsten Pedersen cars...@bitbybit.dk mailto:cars...@bitbybit.dkwrote: On 30-05-2013 09:27, Neil Tompkins wrote: Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil First you need to ask yourself how you expect to use the table in the future. Will you be looking up the data on a regular basis? Or will lookups only be something you will do in exceptional situtions? What is the intended goal of having a UUID for the primary key rather than, say, an integer - or having no PK at all? My immediate thought when reading this was why even store that data in a table? - if it's a simple log, use a log file. Especially if you don't know how you intend to search for data later on. There are many tools that are far superior to SQL when it comes to searching for text strings. You could even consider having a CSV table, which will give you an SQL interface to said text file. / Carsten -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Audit Table storage for Primary Key(s)
There's been a thirst for this kind of thing for sometime but possibly you're looking for a cheaper option? Since 5.5 there's some incarnation of an audit plugin which can be extended for your own needs which should allow you to perform some persistence of the results with either a log file which could be processed into a table before you run your daily query? http://dev.mysql.com/doc/refman/5.5/en/writing-audit-plugins.html http://karlssonondatabases.blogspot.co.uk/2010/03/mysql-audit-plugin-api.html HTH Andy On Fri, May 31, 2013 at 12:05 PM, Carsten Pedersen cars...@bitbybit.dkwrote: Based on the little information available, I would make a lookup field consisting of tablename and primary keys. (although I still believe that storing this information in the database in the first place is probably the wrong approach, but to each his own) / Carsten On 31-05-2013 12:58, Neil Tompkins wrote: The kind of look ups will be trying to diagnose when and by who applied a update. So the primary key of the audit is important. My question is for performance, should the primary key be stored as a indexed field like I mentioned before, or should I have a actual individual field per primary key On Fri, May 31, 2013 at 11:03 AM, Carsten Pedersen cars...@bitbybit.dk mailto:cars...@bitbybit.dk wrote: Again: Unless you can give some idea as to the kind of lookups you will be performing (which fields? Temporal values? etc.), it is impossible to give advice on the table structure. I wouldn't blame anyone for not being able to do so; saving data for debugging will always be a moving target and almost by definition you don't know today what you'll be looking for tomorrow. That's why I think that using CSV tables _the contents of which can subsequently be analyzed using any of a number of text file processing tools_ may indeed be your best initial option. On UUIDs vs. INTs: (1) Please do yourself a favor and read up on how UUIDs are generated. If it's the same server that generates all the UUIDs, you won't get a lot of uniqueness for the amount of space you'll be using for your data and index; (2) Please do the math of just how many inserts you can do per second over the next 1.000 years if you use a longint auto-increment field for your PK. / Carsten On 31-05-2013 11 tel:31-05-2013%2011:14, Neil Tompkins wrote: Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I use UUID because we have currently 54 tables, of which probably 30 will be audited. So a INT PK wouldn't work because of the number of updates we are applying. On Fri, May 31, 2013 at 9:58 AM, Carsten Pedersen cars...@bitbybit.dk mailto:cars...@bitbybit.dk**wrote: On 30-05-2013 09:27, Neil Tompkins wrote: Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil First you need to ask yourself how you expect to use the table in the future. Will you be looking up the data on a regular basis? Or will lookups only be something you will do in exceptional situtions? What is the intended goal of having a UUID for the primary key rather than, say, an integer - or having no PK at all? My immediate thought when reading this was why even store that data in a table? - if it's a simple log, use a log file. Especially if you don't know how you intend to search for data later on. There are many tools that are far superior to SQL when it comes to searching for text strings. You could even consider having a
RE: Audit Table storage for Primary Key(s)
UUID PRIMARY KEY (or even secondary index) -- Once the table gets big enough (bigger than RAM cache), each row INSERTed (or SELECTed) will be a disk hit. (Rule of Thumb: only 100 hits/sec.) This is because _random_ keys (like UUID) make caching useless. Actually, the slowdown will be gradual. For example, once the table is 5 times as big as the cache, 80% (1-1/5) of the INSERTs/SELECTs will hit disk. Bottom line -- Avoid UUIDs in huge tables, if at all possible. (Exception: The bits in type-1 UUIDs can be rearranged to be roughly chronological.) BIGINT -- You cannot possibly hit its max with any existing hardware. MyISAM -- PRIMARY KEY is just another secondary index. Secondary indexes are separate BTrees. InnoDB -- PRIMARY KEY and data coexist in the same BTree. Secondary indexes are separate BTrees. So, assuming this audit table will be huge (too big to be cached), you need to carefully consider every index, both for writing and for reading. You mentioned that you might audit 50 tables? An index that starts with table_name would be inserting/selecting in 50 spots. If the second part of the index is something 'chronological', such as an AUTO_INCREMENT or TIMESTAMP, then there would be 50 hot spots in the index. This is quite efficient. INDEX(table_name, UUID) would be bad because of the randomness. InnoDB may be the preferred engine, even though the footprint is bigger. This is because careful design of the PK could lead to INSERTs into hot spot(s), plus SELECTs being able to take advantage of locality of reference. With PRIMARY KEY(table_name, ...), and SELECT .. WHERE tablename='...', InnoDB will find all the rows together (fewer disk hits); MyISAM will find the data scattered (more disk hits, hence slower). Another aspect... Would your SELECTs say WHERE ... AND timestamp BETWEEN... ? And, would you _usually_ query _recent_ times? If so, there could be a boost from doing both of these ** PARTITION BY RANGE(TO_DAYS(timestamp)) ** Move timestamp to the _end_ of any indexes that it is in. I would be happy to discuss these principles further. To be able to discuss more specifically, please provide ** Your tentative SHOW CREATE TABLE ** how big you plan for the table to become (#rows or GB), ** how much RAM you have -Original Message- From: Carsten Pedersen [mailto:cars...@bitbybit.dk] Sent: Friday, May 31, 2013 4:05 AM Cc: [MySQL] Subject: Re: Audit Table storage for Primary Key(s) Based on the little information available, I would make a lookup field consisting of tablename and primary keys. (although I still believe that storing this information in the database in the first place is probably the wrong approach, but to each his own) / Carsten On 31-05-2013 12:58, Neil Tompkins wrote: The kind of look ups will be trying to diagnose when and by who applied a update. So the primary key of the audit is important. My question is for performance, should the primary key be stored as a indexed field like I mentioned before, or should I have a actual individual field per primary key On Fri, May 31, 2013 at 11:03 AM, Carsten Pedersen cars...@bitbybit.dk mailto:cars...@bitbybit.dk wrote: Again: Unless you can give some idea as to the kind of lookups you will be performing (which fields? Temporal values? etc.), it is impossible to give advice on the table structure. I wouldn't blame anyone for not being able to do so; saving data for debugging will always be a moving target and almost by definition you don't know today what you'll be looking for tomorrow. That's why I think that using CSV tables _the contents of which can subsequently be analyzed using any of a number of text file processing tools_ may indeed be your best initial option. On UUIDs vs. INTs: (1) Please do yourself a favor and read up on how UUIDs are generated. If it's the same server that generates all the UUIDs, you won't get a lot of uniqueness for the amount of space you'll be using for your data and index; (2) Please do the math of just how many inserts you can do per second over the next 1.000 years if you use a longint auto-increment field for your PK. / Carsten On 31-05-2013 11 tel:31-05-2013%2011:14, Neil Tompkins wrote: Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I use UUID because we have currently 54 tables, of which probably 30 will be audited. So a INT PK wouldn't work because of the number of updates we are applying. On Fri, May 31, 2013 at 9:58 AM, Carsten
RE: Audit Table storage for Primary Key(s)
I'll ask the dumb question. Why not create individual history tables corresponding to your 'main' tables? So, if you have an 'address' table, then the original record could be written to an 'address_his' table via an update or delete trigger (depending on whether you allow deletions or not) when a change is made...and the updated address record would be in the 'address' table. The address_his table would really only need two additional fields to track your data - a user field and a journal date/time. Not sure how you're planning on writing to the changes to your audit table, but this would allow the database to do the work instead of having to write application code to do it. Note: This is based on how I see things for the current application where I work. Doesn't mean that it's right or wrong...it just works for us. -Original Message- From: Neil Tompkins [mailto:neil.tompk...@googlemail.com] Sent: Friday, May 31, 2013 3:43 AM To: [MySQL] Subject: Fwd: Audit Table storage for Primary Key(s) Any advice anyone ? -- Forwarded message -- From: Neil Tompkins neil.tompk...@googlemail.com Date: Thu, May 30, 2013 at 8:27 AM Subject: Audit Table storage for Primary Key(s) To: [MySQL] mysql@lists.mysql.com Hi, I've created a Audit table which tracks any changed fields for multiple tables. In my Audit table I'm using a UUID for the primary key. However I need to have a reference back to the primary key(s) of the table audited. At the moment I've a VARCHAR field which stores primary keys like 1 1|2013-05-29 2|2013-05-29 2 3 1|2|2 etc Is this the best approach, or should I have a individual field in the audit table for all primary keys. At the moment I think the max number of primary keys on any given table is 3 Thanks Neil -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Audit Table storage for Primary Key(s)
Ah-ha, excuse my earlier response, I was under the impression you were trying to track schema changes etc. A On Fri, May 31, 2013 at 7:54 PM, Rick James rja...@yahoo-inc.com wrote: UUID PRIMARY KEY (or even secondary index) -- Once the table gets big enough (bigger than RAM cache), each row INSERTed (or SELECTed) will be a disk hit. (Rule of Thumb: only 100 hits/sec.) This is because _random_ keys (like UUID) make caching useless. Actually, the slowdown will be gradual. For example, once the table is 5 times as big as the cache, 80% (1-1/5) of the INSERTs/SELECTs will hit disk. Bottom line -- Avoid UUIDs in huge tables, if at all possible. (Exception: The bits in type-1 UUIDs can be rearranged to be roughly chronological.) BIGINT -- You cannot possibly hit its max with any existing hardware. MyISAM -- PRIMARY KEY is just another secondary index. Secondary indexes are separate BTrees. InnoDB -- PRIMARY KEY and data coexist in the same BTree. Secondary indexes are separate BTrees. So, assuming this audit table will be huge (too big to be cached), you need to carefully consider every index, both for writing and for reading. You mentioned that you might audit 50 tables? An index that starts with table_name would be inserting/selecting in 50 spots. If the second part of the index is something 'chronological', such as an AUTO_INCREMENT or TIMESTAMP, then there would be 50 hot spots in the index. This is quite efficient. INDEX(table_name, UUID) would be bad because of the randomness. InnoDB may be the preferred engine, even though the footprint is bigger. This is because careful design of the PK could lead to INSERTs into hot spot(s), plus SELECTs being able to take advantage of locality of reference. With PRIMARY KEY(table_name, ...), and SELECT .. WHERE tablename='...', InnoDB will find all the rows together (fewer disk hits); MyISAM will find the data scattered (more disk hits, hence slower). Another aspect... Would your SELECTs say WHERE ... AND timestamp BETWEEN... ? And, would you _usually_ query _recent_ times? If so, there could be a boost from doing both of these ** PARTITION BY RANGE(TO_DAYS(timestamp)) ** Move timestamp to the _end_ of any indexes that it is in. I would be happy to discuss these principles further. To be able to discuss more specifically, please provide ** Your tentative SHOW CREATE TABLE ** how big you plan for the table to become (#rows or GB), ** how much RAM you have -Original Message- From: Carsten Pedersen [mailto:cars...@bitbybit.dk] Sent: Friday, May 31, 2013 4:05 AM Cc: [MySQL] Subject: Re: Audit Table storage for Primary Key(s) Based on the little information available, I would make a lookup field consisting of tablename and primary keys. (although I still believe that storing this information in the database in the first place is probably the wrong approach, but to each his own) / Carsten On 31-05-2013 12:58, Neil Tompkins wrote: The kind of look ups will be trying to diagnose when and by who applied a update. So the primary key of the audit is important. My question is for performance, should the primary key be stored as a indexed field like I mentioned before, or should I have a actual individual field per primary key On Fri, May 31, 2013 at 11:03 AM, Carsten Pedersen cars...@bitbybit.dk mailto:cars...@bitbybit.dk wrote: Again: Unless you can give some idea as to the kind of lookups you will be performing (which fields? Temporal values? etc.), it is impossible to give advice on the table structure. I wouldn't blame anyone for not being able to do so; saving data for debugging will always be a moving target and almost by definition you don't know today what you'll be looking for tomorrow. That's why I think that using CSV tables _the contents of which can subsequently be analyzed using any of a number of text file processing tools_ may indeed be your best initial option. On UUIDs vs. INTs: (1) Please do yourself a favor and read up on how UUIDs are generated. If it's the same server that generates all the UUIDs, you won't get a lot of uniqueness for the amount of space you'll be using for your data and index; (2) Please do the math of just how many inserts you can do per second over the next 1.000 years if you use a longint auto-increment field for your PK. / Carsten On 31-05-2013 11 tel:31-05-2013%2011:14, Neil Tompkins wrote: Thanks for your response. We expect to use the Audit log when looking into exceptions and/or any need to debug table updates. I don't think a CSV table would be sufficient as we are wanting to use a interface to query this data at least on a daily basis if not weekly. I
