fix: composite index only created in one table

index name must be unique across database, thus use the new mechanism to
automatically create unique name for same embedded struct

source: go-gorm/gorm#5269

pkg/models/models.go

@@ -8,9 +8,9 @@ import (
 
 type CryptoOHLCV struct {
 	ID            uint            `gorm:"primaryKey"`
-	TradingSymbol string          `gorm:"type:varchar(10);index:idx_tpair_timestamp;not null"`
-	VsCurrency    string          `gorm:"type:varchar(10);index:idx_tpair_timestamp;not null"`
-	Timestamp     time.Time       `gorm:"type:timestamptz;index:idx_tpair_timestamp;not null"`
+	TradingSymbol string          `gorm:"type:varchar(10);index:,composite:tpair_ts;not null"`
+	VsCurrency    string          `gorm:"type:varchar(10);index:,composite:tpair_ts;not null"`
+	Timestamp     time.Time       `gorm:"type:timestamptz;index:,composite:tpair_ts;not null"`
 	Open          decimal.Decimal `gorm:"type:numeric;not null"`
 	High          decimal.Decimal `gorm:"type:numeric;not null"`
 	Low           decimal.Decimal `gorm:"type:numeric;not null"`