Re: [Rails] One huge table or separate tables? design issue
In the Rails world, what Scott wrote is basically right (bordering on insane). ActiveRecord really won't place nice with that kind of a design. Outside of the Rails world, Big Data and Reporting people do things like that (date stamping table names) for aggregate reporting. There are times when those kinds of designs aren't such a bad idea (like you have a massive amount of data and you want to build a reporting engine). But if that's your case, Rails isn't the right tool for you. You could still write a Rails app, but then use some kind of reporting tool to extract data from your Rails database and copy it into another reporting database where you will do your reporting operations (and probably use Crystal Reports or something to deal with that data). On Oct 15, 2014, at 10:58 AM, Scott Ribe scott_r...@elevated-dev.com wrote: On Oct 15, 2014, at 8:44 AM, Yongbiao Long longyongb...@gmail.com wrote: How to deal with the daily created tables in rails? Don't do that. It's an unnormalized, broken, bordering-on-insane design. The date is an attribute of some entity that belongs in its own table, to which your other data is related. Figure out that entity, design it, set up the relationship appropriately between the two. -- Scott Ribe scott_r...@elevated-dev.com http://www.elevated-dev.com/ (303) 722-0567 voice -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/97FDAFF1-402E-4AE6-BED3-AC1F480E5699%40elevated-dev.com. For more options, visit https://groups.google.com/d/optout. Jason Fleetwood-Boldt t...@datatravels.com http://www.jasonfleetwoodboldt.com/writing All material © Jason Fleetwood-Boldt 2014. Public conversations may be turned into blog posts (original poster information will be made anonymous). Email ja...@datatravels.com with questions/concerns about this. -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/4628DB17-2C9E-46DA-8F9E-145D2C4711B3%40datatravels.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
I feel sorry to bother you all again here, but I still have a problem: How to deal with the daily created tables in rails? I googled around and found nothing. The daily created tables are named on the dates, their names are all different. I know how to create tables in a periodically executed rake task. However, I surely cannot define that many(infinite) model classes to manipulate these tables. This question might seem too naive for you, as I asked it in previous posts but got no answers. Hope somebody could give some hints. Thanks again! -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArpxuV0cjAahG8atiJWjUAxcweHurcRNiNpthr7HfJmdcg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On Oct 15, 2014, at 8:44 AM, Yongbiao Long longyongb...@gmail.com wrote: How to deal with the daily created tables in rails? Don't do that. It's an unnormalized, broken, bordering-on-insane design. The date is an attribute of some entity that belongs in its own table, to which your other data is related. Figure out that entity, design it, set up the relationship appropriately between the two. -- Scott Ribe scott_r...@elevated-dev.com http://www.elevated-dev.com/ (303) 722-0567 voice -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/97FDAFF1-402E-4AE6-BED3-AC1F480E5699%40elevated-dev.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On 15 October 2014 15:44, Yongbiao Long longyongb...@gmail.com wrote: I feel sorry to bother you all again here, but I still have a problem: How to deal with the daily created tables in rails? I googled around and found nothing. The daily created tables are named on the dates, their names are all different. I know how to create tables in a periodically executed rake task. However, I surely cannot define that many(infinite) model classes to manipulate these tables. This question might seem too naive for you, as I asked it in previous posts but got no answers. Hope somebody could give some hints. Thanks again! I thought you decided you were not going to have those tables, that you would have a bookings table where each row corresponded to a booking and recorded the journey, start and finish station and seat information. Colin -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLsd_QC9Ts%3DM-%3D3bwXEP28t3%3D-n85JNbdqxkJyNnTjEUSQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
Hi, Creating multiple tables is not the key to solve this problem. If your rows are higher than 10 million records, then you have to make sure you archive the older ( Unused ) rows or solve it through MASTER - SLAVE db approach. Ideally when you're worry about performance issues with databases , it depends on the READ/WRITE speed expected from the db. And how often is the data being stored READ ? Cheers Vivek On Sun, Oct 12, 2014 at 7:02 AM, Yongbiao Long longyongb...@gmail.com wrote: Hi, everyone, I've learned Rails(Web development) on my own for two months, and came to a situation like this: There are two tables A and B in my database. A 'has_many` B. For every user input, There is an entry in table A. At the same time, I need to add a huge number(say 100,000) of entries in B. As table A grows, table B seems to grow uncontrollably. There must be performance issues in later data manipulation operations, or even 'overflow` problems. I use Mysql. My initial thought was to split table B, for example, for every entry in table A, create a new table (on the fly) for it. The questions are: Is my thought right? If yes, then how to design the models and migrations to represent the relationship correctly? If not, what are good practices to solve this kind of problem? I'd be very grateful if you could only give some hints, doc or good articles about it. -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArrsvWhbQ-VXkx-Xj2B16zJbC%2Bg%2BcQpy_S68vO4sJCJG4g%40mail.gmail.com https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArrsvWhbQ-VXkx-Xj2B16zJbC%2Bg%2BcQpy_S68vO4sJCJG4g%40mail.gmail.com?utm_medium=emailutm_source=footer . For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAFKVRj_d-%2BH0UtZZ_ukAd-bdn3d36yOStin%3DFuxTJtn4uroXLQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On 12 October 2014 02:32, Yongbiao Long longyongb...@gmail.com wrote: Hi, everyone, I've learned Rails(Web development) on my own for two months, and came to a situation like this: There are two tables A and B in my database. A 'has_many` B. For every user input, There is an entry in table A. At the same time, I need to add a huge number(say 100,000) of entries in B. As table A grows, table B seems to grow uncontrollably. There must be performance issues in later data manipulation operations, or even 'overflow` problems. I use Mysql. Are you sure your basic design is appropriate? Having 100,000 associated records per user seems very high. Are you able to explain what is in those records in case an alternative can be suggested? Colin -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLs_XsU3fHhomae%3DnM9tiicm%3DRfAiYh0sUXizb6Nb7L14g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On Sun, Oct 12, 2014 at 5:17 PM, Colin Law clan...@gmail.com wrote: Are you sure your basic design is appropriate? Having 100,000 associated records per user seems very high. Are you able to explain what is in those records in case an alternative can be suggested? Thank you Colin! I'm implementing a railway ticket-booking system just for learn purpose, not for production. Now I try to explain it: Suppose a train has 20 stations along the way. It has 1000 seats to sell. Table A store one train's information in a row. I want table B to store every seat's information. I design table B as follow train_id: start_city_id: end_city_id: seat_id: availability: boolean type date: For one train, the number of start_city_id and end_city_id's combinations is 19+18+...+1=190, the number of possible date is 20(people can book tickets in 20 days), and possible seat_id's number is 1000. The total number of rows for one train is 190*1000*20=3,800,000. So huge.. Actually I have more tables in database which are omitted as they are unrelated. Maybe I should compute the state of any seat every time the system issues a seat? (Some words on the state of a seat: A train goes by city L, M, N, O and there is only one seat left. If a person has booked M-N's seat, then L-O is not available, but L-M, N-O is.) -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArrOjR83tod-JgQ--ESvMJgu0ip7nGj6i0cQibjXS5qNWQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On 12 October 2014 11:34, Yongbiao Long longyongb...@gmail.com wrote: On Sun, Oct 12, 2014 at 5:17 PM, Colin Law clan...@gmail.com wrote: Are you sure your basic design is appropriate? Having 100,000 associated records per user seems very high. Are you able to explain what is in those records in case an alternative can be suggested? Thank you Colin! I'm implementing a railway ticket-booking system just for learn purpose, not for production. Now I try to explain it: Suppose a train has 20 stations along the way. It has 1000 seats to sell. Table A store one train's information in a row. I want table B to store every seat's information. I design table B as follow train_id: start_city_id: end_city_id: seat_id: availability: boolean type date: For one train, the number of start_city_id and end_city_id's combinations is 19+18+...+1=190, the number of possible date is 20(people can book tickets in 20 days), and possible seat_id's number is 1000. The total number of rows for one train is 190*1000*20=3,800,000. So huge.. The first point is that you should only add rows as seats are booked, use that fact that there is no row to indicate that there is no booking. Secondly, what is the date? Is that the date of the journey or the date of the booking? I don't understand why you have multiplied the number of trains by 20 days. If it is the date of the journey then consider having a Journeys table which is a particular train on a particular day. Thirdly I don't understand why you have 20 factorial for the city combinations. Is it not true that if a seat is booked from station 1 to station 3 then that implies a booking 1 to 2 and 2 to 3? In which case you do not separate rows for bookings 1 to 2, 2 to 3, and 1 to 3. Actually I have more tables in database which are omitted as they are unrelated. Maybe I should compute the state of any seat every time the system issues a seat? (Some words on the state of a seat: A train goes by city L, M, N, O and there is only one seat left. If a person has booked M-N's seat, then L-O is not available, but L-M, N-O is.) -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArrOjR83tod-JgQ--ESvMJgu0ip7nGj6i0cQibjXS5qNWQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLsXF428u1JXtxjg1exvK2U7j_W7E3-ExMoPCDQ%3D7bJ%2BwA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On 12 October 2014 11:54, Colin Law clan...@gmail.com wrote: On 12 October 2014 11:34, Yongbiao Long longyongb...@gmail.com wrote: On Sun, Oct 12, 2014 at 5:17 PM, Colin Law clan...@gmail.com wrote: Are you sure your basic design is appropriate? Having 100,000 associated records per user seems very high. Are you able to explain what is in those records in case an alternative can be suggested? Thank you Colin! I'm implementing a railway ticket-booking system just for learn purpose, not for production. Now I try to explain it: Suppose a train has 20 stations along the way. It has 1000 seats to sell. Table A store one train's information in a row. I want table B to store every seat's information. I design table B as follow train_id: start_city_id: end_city_id: seat_id: availability: boolean type date: For one train, the number of start_city_id and end_city_id's combinations is 19+18+...+1=190, the number of possible date is 20(people can book tickets in 20 days), and possible seat_id's number is 1000. The total number of rows for one train is 190*1000*20=3,800,000. So huge.. The first point is that you should only add rows as seats are booked, use that fact that there is no row to indicate that there is no booking. Secondly, what is the date? Is that the date of the journey or the date of the booking? I don't understand why you have multiplied the number of trains by 20 days. If it is the date of the journey then consider having a Journeys table which is a particular train on a particular day. Thirdly I don't understand why you have 20 factorial for the city combinations. Is it not true that if a seat is booked from station 1 to station 3 then that implies a booking 1 to 2 and 2 to 3? In which case you do not separate rows for bookings 1 to 2, 2 to 3, and 1 to 3. In fact thinking further, I would probably turn the problem around and have a bookings table, specifying the journey, the stations, and the seat (or seats). Colin -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLv77Kt-sH6rw0djfqrkNUycnkTimEw6anNg_oZSg-YOYg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
you can also run a task that archives past dates to a duplicate table since you'll rarely need them. maybe you can keep 1 month data in the table that you're writing to. this way, you won't have to worry about the exponential growth of the table you're always accessing. On Sun, Oct 12, 2014 at 7:12 PM, Colin Law clan...@gmail.com wrote: On 12 October 2014 11:54, Colin Law clan...@gmail.com wrote: On 12 October 2014 11:34, Yongbiao Long longyongb...@gmail.com wrote: On Sun, Oct 12, 2014 at 5:17 PM, Colin Law clan...@gmail.com wrote: Are you sure your basic design is appropriate? Having 100,000 associated records per user seems very high. Are you able to explain what is in those records in case an alternative can be suggested? Thank you Colin! I'm implementing a railway ticket-booking system just for learn purpose, not for production. Now I try to explain it: Suppose a train has 20 stations along the way. It has 1000 seats to sell. Table A store one train's information in a row. I want table B to store every seat's information. I design table B as follow train_id: start_city_id: end_city_id: seat_id: availability: boolean type date: For one train, the number of start_city_id and end_city_id's combinations is 19+18+...+1=190, the number of possible date is 20(people can book tickets in 20 days), and possible seat_id's number is 1000. The total number of rows for one train is 190*1000*20=3,800,000. So huge.. The first point is that you should only add rows as seats are booked, use that fact that there is no row to indicate that there is no booking. Secondly, what is the date? Is that the date of the journey or the date of the booking? I don't understand why you have multiplied the number of trains by 20 days. If it is the date of the journey then consider having a Journeys table which is a particular train on a particular day. Thirdly I don't understand why you have 20 factorial for the city combinations. Is it not true that if a seat is booked from station 1 to station 3 then that implies a booking 1 to 2 and 2 to 3? In which case you do not separate rows for bookings 1 to 2, 2 to 3, and 1 to 3. In fact thinking further, I would probably turn the problem around and have a bookings table, specifying the journey, the stations, and the seat (or seats). Colin -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLv77Kt-sH6rw0djfqrkNUycnkTimEw6anNg_oZSg-YOYg%40mail.gmail.com . For more options, visit https://groups.google.com/d/optout. -- - visit my blog at http://jimlabs.herokuapp.com -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAJ8y7Vf2ShaMFvah%2B0%3DWv%3DWqdrhWH_f5Zgi2bNLuL%3DHPziVOyQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On Sun, Oct 12, 2014 at 6:54 PM, Colin Law clan...@gmail.com wrote: The first point is that you should only add rows as seats are booked, use that fact that there is no row to indicate that there is no booking. Secondly, what is the date? Is that the date of the journey or the date of the booking? I don't understand why you have multiplied the number of trains by 20 days. If it is the date of the journey then consider having a Journeys table which is a particular train on a particular day. It's the date of the journey. I once thought about this method, the problem is I don't know how to implement it in rails. In Rails tutorials and guidelines, there is a model file in app/model directory for every table. If I need to create new journey tables, what's the model files and migration files look like?(Or I don't need them any more?) Thirdly I don't understand why you have 20 factorial for the city combinations. Is it not true that if a seat is booked from station 1 to station 3 then that implies a booking 1 to 2 and 2 to 3? In which case you do not separate rows for bookings 1 to 2, 2 to 3, and 1 to 3. According to your first and third point, It's because my design is different. In my design one booking might indicates more than one row. A row just means the state of a seat. So, if a seat is booked from station 1 to station 3, then rows representing 1-3, 1-2, 2-3, 1-4, 1-5 all need to change. I do it in this way because I have another table representing the number of left seats, and I think it's easier to update this table in my way(in this case, the number of leaf seats from 1-3, 1-2, 2-3 decreases by one). Thank you for your suggestion! I'll dig it deeper and reveal my concerns. -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArpqTg%2B9ot_bTLAB8jyse7JW9wT%3DMCaN0gArogHgKUB6yg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On Sun, Oct 12, 2014 at 7:18 PM, Jim Ruther Nill jvn...@gmail.com wrote: you can also run a task that archives past dates to a duplicate table since you'll rarely need them. maybe you can keep 1 month data in the table that you're writing to. this way, you won't have to worry about the exponential growth of the table you're always accessing. Yeah, I've also plan to do this kind of thing. Thank you anyway;-) -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArqJuvmJ_BDWa%2Bknhnppuuad7feiM-k_-HaW2zu5a7MfZQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On Sun, Oct 12, 2014 at 7:28 PM, Yongbiao Long longyongb...@gmail.com wrote: I do it in this way because I have another table representing the number of left seats, and I think it's easier to update this table in my way(in this case, the number of leaf seats from 1-3, 1-2, 2-3 decreases by one). This computation process seems the same for both our table designs... I'll use your approach, having a bookings table, specifying the journey, the stations, and the seat (or seats). -- Best Regards -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CALDAArpMqkWBHpJ7AmXoy34C13Uqc25g8aq_FzDaq%3DBPRerUJA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [Rails] One huge table or separate tables? design issue
On 12 October 2014 12:28, Yongbiao Long longyongb...@gmail.com wrote: On Sun, Oct 12, 2014 at 6:54 PM, Colin Law clan...@gmail.com wrote: The first point is that you should only add rows as seats are booked, use that fact that there is no row to indicate that there is no booking. Secondly, what is the date? Is that the date of the journey or the date of the booking? I don't understand why you have multiplied the number of trains by 20 days. If it is the date of the journey then consider having a Journeys table which is a particular train on a particular day. It's the date of the journey. I once thought about this method, the problem is I don't know how to implement it in rails. In Rails tutorials and guidelines, there is a model file in app/model directory for every table. If I need to create new journey tables, what's the model files and migration files look like?(Or I don't need them any more?) Thirdly I don't understand why you have 20 factorial for the city combinations. Is it not true that if a seat is booked from station 1 to station 3 then that implies a booking 1 to 2 and 2 to 3? In which case you do not separate rows for bookings 1 to 2, 2 to 3, and 1 to 3. According to your first and third point, It's because my design is different. In my design one booking might indicates more than one row. A row just means the state of a seat. So, if a seat is booked from station 1 to station 3, then rows representing 1-3, 1-2, 2-3, 1-4, 1-5 all need to change. I do it in this way because I have another table representing the number of left seats, and I think it's easier to update this table in my way(in this case, the number of leaf seats from 1-3, 1-2, 2-3 decreases by one). In that case you have redundant data in your database (as 1-3 implies 1-2 and 1-3), which is almost always not the best way to do it. Colin -- You received this message because you are subscribed to the Google Groups Ruby on Rails: Talk group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-talk@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAL%3D0gLvwrGm5H1V4jmJko9fXeJbOAFAj7GhfkvnepEcrzxDH0g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
